There does not seem to be any statement within the film Terminator 2:  Judgment Day concerning what year anything happens.  We extrapolate it from what we know from the original film The Terminator and what we are told in Terminator 3:  Rise of the Machines, but there are some serious problems.  Here are the dates we know:

• The first terminator arrived May 12th, 1984, intent on killing Sarah Connor.
• It was sent from sometime in 2029.
• Judgment Day was reported to be August 29th, 1997.
• Skynet was actually online before that, August 4th, 1997.
• The T-X arrived on July 24th, 2004.
• Marcus Wright donates his body to Cyberdyne research in 2003; he emerges during the fighting in 2018.
• John Connor was killed in 2032.

Now we have a lot of other markers that should tie things together relative to each other, and we start to get into trouble.

• In 2004, John says that Cyberdyne was destroyed "over ten years ago" and "about ten years ago", which puts that not later than 1994, possibly 1993.
• Sarah's crypt says she was interred in 1997, and John says she lived long enough to be certain that Judgment Day did not happen.  However, he also says that she lived three years after being diagnosed with leukemia, and that they were living in Baja at the time.  This puts the diagnosis in 1994, and means she was already out of the mental hospital by then.  (Had she been diagnosed with leukemia while in the state mental hospital or before being admitted there, she would have been receiving treatment for it.)  Thus her escape must have been early in 1994 at the latest.

Unfortunately, that does not resolve the matter.

• Kate Brewster says that the night before the events of Terminator 2 the two of them "made out" in Mike Kripke's basement, and that they were students together at West Hill Junior High School.  In the United States, junior high schools usually include eighth and ninth graders, sometimes seventh or tenth graders, rarely sixth graders.  Americans typically begin kindergarten at five years old.  Since John was conceived in May, 1984, he was born in February or March, 1985, and began kindergarten at five years old in 1990.  Conveniently for the math he would have started first grade in 1991, and that means he would be in fourth grade in the fall of 1994; he would not be in junior high until 1996 at the earliest, and probably not until 1997, when he was twelve.  That, though, is only seven years before 2004.

There is one more complication.

• In Terminator 2 the protector says he was sent back "thirty-five years".  We reasonably believe that the first terminator was sent from 2029; if the second was also sent from 2029, it would arrive in 1994.  However, even though in the opening moments of Terminator 2 Sarah Connor tells us that SkyNet sent two terminators, we are certain that they were not sent from the same moment in the future.  When the first terminator was sent, it was the most advanced model then available.  Before the moment of departure in the second film, SkyNet has to develop the T-1000 and the resistance has to capture and reprogram a T-800.  The window is narrow, though--in Terminator 3 we are told that John Connor is killed in 2032, and thirty-five years before that is 1997, but again there is a sense that the T-X is a later development than the T-1000, which probably puts us back to 1996.

So we are caught in a bind.  All the future dates seem to push us to a 1994 date for the Terminator 2 events, particularly that Sarah must have escaped from the lockdown not later than that year, but John will not be old enough to be that character until 1997, 1996 at the earliest--unless we think that he skipped a few grades of elementary school despite the fact that his mother kept moving him around and was not interested in whether he learned his college prep subjects.

This is not the only place where the Terminator franchise plays fast and loose with its dates.  In Terminator Genisys Sarah says (in separate sililoquys) that Pops saved her in 1973 when she was 9; in Terminator 3, though, her grave marker gives her lifespan as 1959-1997, which means she turned 14 in 1973.  As important as dates are to time travel fans and the analysis of events, they do not seem to matter much to the filmmakers.

Its impact on the present analysis is really only that it makes it very difficult to discuss some critical elements in the anomalies, because we have to refer to trips to that time and what happens to them when Sarah and Kyle drastically change history.  For convenience, we will assume that Terminator 2 happened in 1996, and acknowledge that that date is as impossible as every other one.

Terminator Genisys, long anticipated, has now run its course through theatres, and a video copy has reached the Temporal Anomalies desk; we had already begun this analysis based on having seen it once in the theatre and obtaining a copy of the audio from which notes were made, but have since viewed the DVD and reviewed portions and materials from previous films.  Hopefully we have not missed any important details.

Although in the past we have praised the Terminator franchise for its ability to address complicated temporal issues and create possible outcomes, this movie is both confused and confusing on the temporal count.  Don't misunderstand--it is a wonderfully entertaining movie, and it raises many interesting ideas about time travel, but ultimately it fails to put forward a coherent temporal theory.  The creators were great at chase and action sequences and at dramatic plot, but had no conception of how time travel works under any plausible theory.

As a result, our analysis will also be complicated and perhaps a bit confusing, but we will begin with a few of the problems to which we will return, then attempt a summary of the story as it unfolds.  Consider this the spoiler alert.

We begin in about 2013, as an adult John Conner rescues a perhaps nine-year-old boy named Kyle Reese, and then Kyle reaches adulthood as they are expecting to hear of the destruction of Skynet's central core and headed for the location of the secret temporal weapon.  This is the critical future end of the first film, said to be 2029, the moment at which Skynet sends a T-800 model 101 from 2029 to 1984 to kill Sarah Conner, and John is about to send Kyle back to protect her.  John says that at this moment all his knowledge ends, because Sarah knew nothing beyond this point (our first problem); he sends Kyle back, but is attacked by some kind of advanced terminator as Kyle is vanishing (our second problem).

When the T-800 reaches 1984, we see some of the original movie, but then an aged T-800 appears and, working with someone unseen who proves to be Sarah, the older model, dubbed "Pops", destroys the younger (and we have several more problems).  The duo then runs across town to save Kyle from a waiting T-1000 (another problem), luring the advanced terminator into a trap so they can destroy it.  They use the processor from the destroyed T-800 to control their own time machine.  Sarah wants to leap forward to 1997 to stop Skynet before it starts, but Kyle seems to have picked up memories from an alternate self in an alternate timeline telling him that Genisys is Skynet and he has to stop it in 2017 (and we have several more problems).  He persuades her by telling her what she has not yet told him (more problems), and they leap to 2017.  They are met there by a version of John Conner who has been coopted by nanites into a new kind of machine (and that's another problem) but they defeat him, destroy Cyberdyne and the Skynet and time machine work there, and go to visit the young Kyle Reese to give him the message that the older Kyle Reese has to remember (yes, an obvious problem).  Then it appears that Kyle and Sarah are finally going to get together and have that kid (and that's a problem, too), and the movie ends.

There are clear indications that a sequel is intended:  "Pops", the T-800 who has been protecting Sarah since she was nine, gets upgraded in the explosion because he is in a vat of poly-alloy and so becomes something more like a T-1000; and beneath the wreckage of Cyberdyne there is what seems to be the residue of the Skynet operating system.  So they probably already have a next story concept in mind, and will begin working on the film soon.

With that outline, we will attempt to explain and address the problems.  At the core, though, the central problem is that there are plausible explanations for nearly every one of these events, except that they require events which cannot happen together in the same history of the universe.  Something akin to Dr. Manhattan's multiverse might work, but that gives us a very unsatisfying story ultimately.

We have often faced the issue of how it is that a time traveler can remember events which he has caused never to have happened, but not those events through which he must actually have lived.  We most recently addressed it in Project Almanac, saw it in a big way in X-Men:  Days of Future Past, saw it in About Time--indeed, it was a problem all the way back in the original Back to the Future film.  In short, if Marty left 1985 for 1955 and changed events such that his entire life was slightly different, the Marty who returns to 1985 has to be the only one who was ever born, the one who lived through this different life.  When the other history is erased and replaced, there must be a Marty who lived through that history, and there cannot be one who lived through the now erased history--he was erased and replaced along with it.  So memory problems are nothing new as time travel problems go.

Yet this is a new one.

Kyle Reese remembers events from the childhood he is about to create.  He has told us that he was born after the bombs fell (a problem we addressed twice in discussing Terminator Salvation) and that he never knew that peaceful green world of which he had heard stories.  Yet suddenly he has memories of such a world, a world in which the bombs never fell and he was coming to a thirteenth birthday.  These are memories of a history that has not yet happened, and cannot have happened in any universe in which Kyle was born after the bombs fell.  This is not the sort of memory issue we usually see, where those events happened in a previous (now erased) version of history through which the time traveler lived.  This is a memory of events that happen in a history that has never happened, a history contingent at least in some ways on our time traveler surviving to become part of it.

We might look to the Doctor Manhattan type of multiverse, in which all possible worlds exist and this one character has memories from more than one of them.  Yet if we do, we need to ask ourselves in what sense a world can exist.  In order for Kyle to born in 2005 in a world in which the bombs never fell, both the 1997 and the 2004 launches of Skynet must be thwarted.  We are looking at memories of a timeline which cannot by any known chain of events come into existence, which cannot have come into existence yet, and which this version of Kyle could never have experienced even if somehow it had.

The film offers the pseudo-rational explanation (and I generally have a lot of respect for pseudo-rational explanations in science fiction films--how do we know that it did not work that way?) that Kyle could have memories of multiple timelines if he experienced a nexus point.  What does that mean, and does it makes any sense?

We are told that if Kyle were present at a "nexus point" he might have memories from another timeline.  A "nexus point", we are told, is a moment when the future is altered.  The conclusion is that when John Conner is compromised by the T-5000, that changes the future in a major way, and the result is that Kyle gets these other memories.

I maintain a low bar for pseudo-rational explanations, but this one does not really withstand even modest scrutiny.

The critical problem is the issue of at what moment history is altered in a critical way.  The fact is, history does not know it is being altered--in 2029 when the T-5000 is attacking John, the universe does not really know that this is not the original history; in 2029, 2030 has not yet happened, and whatever happens is the creation of history, not its alteration.  The notion of changing the future, even of changing the present, is on one level nonsense.  We can speak of changing the past, but from the perspective of the past, we are not changing anything but forming something.

So what is meant must be that something happens in history informed by causes from the future; that some time traveler has had a significant impact on history.  The problem then, though, becomes how the universe knows whether any particular act is "significant".  A time traveler is standing on a grassy hill holding a device.  He was not there in the original history, and so he has changed history, creating a new version.  Is it significant that he is there at all?  Is it significant if he is taking pictures of the President of the United States at the moment the man is fatally shot, so that in the future these can be studied to answer questions about that assassination?  Is it significant if he is the one who shoots the President?  There is a sense in which the assassination of a President is a major moment in history; there is another sense in which people orbiting Rigel (if there are any people orbiting Rigel) are completely unaffected by it.  Significance is always a matter of degree and perspective.  To say that a T-5000 compromising John Conner is more significant than a T-5000 taking a wrong turn on main street and getting lost is a value judgment the universe and the laws of physics cannot make.  If there is such a thing as a change to history, all changes are in that sense equal, whatever their impact on time otherwise.

That means that from the moment a time traveler arrives, he is changing events in significant ways, and therefore every moment from the moment of his arrival is a nexus point in that sense.  We know that Kyle lands in a past in which machines have arrived from his future, and therefore every moment from 1973 (the arrival of Pops) to the hypothetical end of time is a moment in which history is being changed by the actions of time travelers.  Is it different due to spatial proximity?  Why?

The only thing that might might make sense is that the T-5000 arrived, temporally, at the same moment Kyle was departing.  After all, the moment at which the past changes is very much the moment at which the time traveler arrives from the future--everything he from the perspective of that moment is going to do he from the perspective of his departure time will already have done.  This is the moment at which he changes history.  That is not the sense we have of this event--and indeed, the specific history Kyle remembers is caused not by the T-5000's arrival, but by another trip which its arrival causes--but then, the T-5000 does seem to come from nowhere, and the lack of any fireworks accompanying its arrival might mean only that the process has improved.  Still, it does not sit well; it does not seem to be what Pops seems to mean.  And what Pops seems to mean does not make sense.  The explanation for why Kyle, impossibly, remembers events from the future history of a timeline which he must first create does not pass muster.

As the film begins, we come to the critical moment in 2029 when a T-800 has been sent to kill Sarah Conner in 1984, and John Conner is about to send Kyle Reese back to defend her.  We have the sense that John already knows he is sending Kyle, that he knows Kyle is his father, and that the events of the first film are, to some degree, known to John.  However, John explains at this point that his famous prescience is based on the fact that Sarah told him everything she learned from Kyle, and that that information ends tonight--and we at that moment should balk.  Certainly Sarah got a substantial amount of information about the future from Kyle Reese, but she got more from the T-800 sent back to protect John somewhere around 1996.  Why does John not have that information?

In our reconstruction, we recognized that there had to be an original history in which no one arrived from the future, followed by a version in which some model terminator was sent to kill Sarah which she somehow managed to evade, and then that Kyle was sent to protect her; we also noted that there would be a ratcheting of seriousness, that the original terminator would not be the one in the movie but a lesser version which is ultimately enhanced by the sawtooth snap created when Cyberdyne gets pieces of that machine and accelerates the development of a better machine, giving it pieces of the better machine.  All of this, we said, has to stabilize into a history in which the same machine and the same person are sent to the same moments in the past before we can move forward.  Thus that has to become a stable version of history before we can advance however long it is into the future to the moment when the T-1000 is sent to kill John and the second T-800 is sent to protect him.  Thus there is a history (or several histories) in which at this moment the future has never happened in any sense, no other terminators have been sent to the past, and John Conner's information ends here.  This would be true in those histories.

The problem is, this is not one of those histories.  Several things are about to occur which demonstrate conclusively that this was not the endpoint of this history.  Yet if that is so, why does John not have additional information about the future?  What happened to the knowledge gained from the T-800 in 1996?

Kyle Reese leaves from 2029 targeting 1984.  John Conner has told him much of the history of 1984:  Sarah Conner is a timid girl, a waitress (whatever that was) who cannot imagine needing protection.  However, Kyle arrives in a world in which there are already several terminators, one of them, Pops, belonging to Sarah, and she has been trained for a decade to destroy the things and waiting to pick up Kyle.  Why did Kyle not land in his own history?  Why did John not know any of this?  It is certainly plausible that after Kyle was sent to the past, someone else came from the future and changed the past before his moment of arrival--but if, in a metaphysical sense, that had already happened "before" he left, then that would be the history everyone would know; and if in that same sense it had "not happened yet" then Kyle should have arrived in the past he knew.  Certainly it is possible for the history of his arrival to change, but then the history of his departure must also change.

There seems to be a plausible answer, that the future has happened, but that that future has been altered in a way which has eliminated the attempt to kill John in 1996.  That has severe ramifications, of course.  John had come to believe that his mother was crazy, and it was only the arrival of the two terminators that year that caused him to recognize that as paranoid as she was they were actually out to get her.  This also fits with the ambush by the unidentified terminator (online sources label it a T-5000) that attacks John as Kyle is departing, a model more advanced than anything available at that time and therefore one sent from a future.  If we assume that Skynet sent the T-800 back to kill Sarah as a lure to bring John Conner here, and that it either could not or did not prevent Kyle from following but instead took over John at this point, then from this point forward John works for Skynet, and there is no reason for Skynet to attempt to kill him (or Sarah) in 1996 or 2004, and those trips are never made.

Unfortunately, the only reconstructions in which the 1996 events are erased are those in which Pops arrived in 1973, so this solution fails.  However, there is a history from which Kyle is sent in which there are not yet any 1996 events, and that departure is not yet erased until the new history reaches that point.  Thus Kyle could have been sent from a history that is being erased, if there proves to be one that fits John's knowledge.

No, it is not as simple as that; it is a mess.  This only gets us a possible solution to the first problem.  As will appear, histories in which this is possible do occur, but only within complex infinity loop outcomes which destroy time.

When Kyle Reese reaches 1984, there are several surprises waiting for him.  The biggest problem for us, though, is that there is a T-800, known affectionately by Sarah Conner as "Pops", already protecting her.  His concerns seem to be that Sarah survive and "mate" with Kyle so that John Conner would be born in the future.  He arrived in 1973 and protected her from a T-1000 that had been sent to kill her as a child--and our alarm bells go off everywhere.

In the original movie, a significant part of the point--and the primary advantage Kyle had--was that Skynet did not know anything about Sarah prior to the fact that she was one of several persons of that name living in Los Angeles in 1984.  Now suddenly a T-1000 has been sent back eleven years earlier to target the girl whose history was completely unknown.

As an aside, kudos to the filmmakers for thinking of something that perhaps should have been obvious before now.  Every previous time trip has sent its traveler to a time after the one before--the T-800 leaves first and arrives first, Kyle leaves second and arrives second, the T-1000 sent next is sent back to a later time, and the T-800 guardian leaves and arrives later, the T-X leaves and arrives later still, and the second protector is sent back after that and arrives after that.  No one ever thought to send a time traveler to an arrival time earlier than the arrival of any previously departing time traveler.  As an analyst, I'm grateful for that--it makes the anomalies considerably simpler.  On the other hand, it seemed a silly oversight, and now they have remedied it, sending quite a few time travelers to earlier moments.  So the idea of sending a terminator back to kill Sarah earlier is something that makes perfect sense.  There was never a suggestion that it was technologically impossible; it was a matter of information.

But that is still the problem.  No one knows who Sarah was or where she was at any time prior to 1984 Los Angeles, unless it is John himself.  That means the only way Skynet can get that information is from John.  However, once Skynet has compromised John, there is no reason to kill Sarah--Skynet now needs Sarah to give it John.  The same logic that led it to attempt to kill Sarah before John was born now must lead it to keep Sarah alive.

There might be another way, though.  Let us extrapolate that there is a future between 2029 and the moment the T-5000 is sent to compromise John.  This is the history from which the T-1000 and T-X were sent.  We further assume that in this history John tells Kate Brewster Conner some of the things he knows about his mother's history before he is killed in 2032.  At that point, Kate decides to send a T-800 to protect Sarah, prophylactically--but in doing so reveals who and where Sarah is.  The result is that Skynet has a target, and sends a T-1000 to kill her.

This solves one of the biggest problems of the 1973 scenario:  how did nine year old Sarah survive the relentless assault of a T-1000?  We assume the usual scenario, that a Terminator is sent first and a protector is sent second, but as we have seen before under that arrangement it must be the case that the target survives the first history unassisted--once the terminator leaves from the future, all of history must be rewritten based on its arrival in the past before the protector can be sent, and if the terminator succeeds the target will not have existed to become a problem, and the guardian will never be sent.  Yet if someone, Kate our nominee, sends a protector first, then we have a history in which the protector is already there when Kyle arrives (and a very different history from that), and an explanation for how Skynet got the location of young Sarah, and the scenario is now that the protector was already there in the past to protect Sarah when the T-1000 arrived.

That does not explain how a T-800 and a nine-year-old girl defeated a T-1000, but at least it's better than trying to understand how a nine-year-old girl did it herself.

It should also be noted that this makes a fixed time theory solution to the film impossible:  the time travelers are changing the past, and they are fully aware that they are doing so.  That is a separate problem.

Once we accept that there is a missing future time segment from which a T-800 and a T-1000 were sent back to 1973, it becomes easier to resolve the issue of the appearance of the T-1000 as a police officer in 1984.  It, too, was sent back during that window, and it makes good sense to assume that Skynet would take such a step to stop Kyle Reese, as long as Skynet has not yet coopted John Conner to its side.

We might wonder why Skynet did not send a T-1000 to kill Sarah instead of a T-800, but the answer to that is simple:  at the time that Skynet activates the time machine to target Sarah in 1984, the T-800 is the most advanced terminator yet developed.  When it has T-1000s it starts sending them back.  The bigger question is why a T-X was never sent to destroy Pops, but since when Sarah is captured in 2017 there is no record of her ever having existed, we can safely conclude that Pops managed to keep both of them so far off the grid that they could never be targeted from the future after that moment of departure.

Yet the presence of the T-1000 in 1984 raises more questions:  Skynet can presumably send any number of terminators to any points in history; why does it not do so?  Is there a problem that prevents upper level terminators from working together (we see earlier models doing so in earlier films)?  Is there a resource shortage that limits how many advanced models it can construct (it appears to have them warehoused), or how many times it can use its own time machine?

The conflict has escalated, but in very significant ways it has not escalated enough.

When we did our original analysis of Terminator and Terminator 2:  Judgment Day, we observed that there must have been an original history in which someone who was not Cyberdyne created and launched the original version of Skynet, and that when the T-800 was destroyed leaving pieces in Cyberdyne's facilities, the tech company was able to get ahead of the original creator and launch Skynet ahead of schedule.  With Terminator 3 we concluded that the original developer was the United States Air Force Cyber Research Systems Autonomous Weapons Division, headed by General Brewster, and that it went online in 2004.  Although the presence of the T-X from the future helped facilitate this and gave it control over a greater arsenal than it would originally have had, there is no indication that this launch was in any way caused by any actions from the future:  this is what happens if no one interferes.

That 2004 launch date looms as a problem over the entire film.  Once Sarah and Pops destroy the T-800 in 1984, they have prevented the 1997 launch, so that does not become a problem.  We assume that Pops has been given the 1997 launch date as the history even when it has been replaced by the 2004 launch date.  The problem is, how do we remove the 2004 launch date and wind up with a 2017 date?

We might resolve this with a major reconsideration.  We recognized in the very first analysis that there must have been an original origin of Skynet, and that Cyberdyne interfered and became the new origin of an earlier version of the system.  With Terminator 3 we saw that the United States Air Force and General Brewster launched a software version of Skynet, a sophisticated antivirus program that became infected with the virus it was intended to attack and immediately became sentient and decided to conquer the world.  On that analysis, if the 1997 Cyberdyne version does not launch, then the 2004 Autonomous Weapons Division version does instead.  That means there will be a version of Skynet running a good baker's dozen years before 2017, at minimum.

Is there an alternative reconstruction?  There might be.

From the moment in 1984 when they found those future parts in their machinery to the moment in 1997 when Skynet launched, Cyberdyne was working on a project that was intended as a secret project for the government.  They would have played their cards close to their breast, but would have had to have given progress reports along the way.  That means that the Air Force was anticipating the development of Skynet before 1997 and had some information from it.  We suggested the possibility that some of that information went into the development of those autonomous weapons which the T-X commandeered in Terminator 3.  However, it is not impossible that they also got information that led to the software progress in that branch, even the creation of that branch.  That means the 2004 launch is also caused by the Cyberdyne research on those future parts.  There is an original history in which Skynet did not exist even in 2004, but went online later in some way not revealed.  It might have happened in 2017, but it was probably later; John Conner, born in 1985, was not younger than thirty-two when it happened.

What this means is that when Sarah destroys Cyberdyne in 1996, she prevents the 1997 launch but leaves the Air Force with a lot of material from which it can cause the 2004 launch; but when she destroys the T-800 in 1984 so that Cyberdyne never sees the pieces, she eliminates that information, and there is no Autonomous Weapons Division and no 2004 Skynet.  Skynet must come into existence some other way at a later time.

So does that give us the 2017 launch?  That seems doubtful.  It is not impossible, but Myles Dyson comments that John Conner--the John Conner who came from the future--contributed code to the system that not even Danny Dyson understands.  That means that we again (as in 1997 and, apparently, 2004) have a version of Skynet that launches earlier than it originally did because someone brought technology from the future.

With the advent of Terminator 3:  Rise of the Machines and the introduction of General Robert Brewster's United States Air Force Cyber Research Systems Autonomous Weapons Division we assumed we had found the original launch in 2004.  Now we theorize that this was not the original date, but another early date based on some of Cyberdyne's research into the T-800 parts which made it to the Air Force before being destroyed, which became part of and led to the 2004 launch.  That means that we are back to the same position in which we were after the first two films:  there was an original launch date from an original cause, and we have very little information to tell us when that is.

We also conclude that it is probably not the 2017 launch.  This is unfortunate, because if we could assume that Genisys was the original Skynet we might have a longshot guess at how that information could have reached Kyle Reese.  It is not very rational to think that information from a long-erased original history of the world could land in the mind of a time traveler traveling from a history in which it never happened, but that's considerably more likely than that information from a history that has not yet ever occurred could do so.  That, though, is a separate problem.  This problem is establishing a date for the Skynet launch--and they have not made it very easy.

Our one certainty is that it must be after 2017, because otherwise the elimination of the 2004 launch would have caused history to default to the original launch, and the 2017 "Genisys Is Skynet" launch would not have happened.

Our next guess is that it must have been before 2029, because that is when Skynet sends the T-800 back to kill Sarah Conner; therefore it would seem that Skynet must be well enough established that it has its time machine but has not used it, has built terminators and developed the T-800, and has started losing the war against humanity.  It is also necessary that there be someone who is Sarah Conner's child important enough within the resistance that killing Sarah Conner in 1984 to prevent that birth is the single best tactical move Skynet can identify at that moment.

However, it could be far more convoluted than that.  With a tip of the hat to Timothy Fox (who long ago suggested that there might be a different original history--and while I stand by my answer there, something like that may be happening here), it might be that in the original history there was no Skynet until still further in the future, that Sarah and John Conner were irrelevant, Kyle Reese, if he existed, lived an ordinary life, and perhaps in 2050, perhaps in 2080, Skynet came into existence.  That future Skynet then had reason to send one of its terminators back to kill someone who was going to become a problem (or the mother of a problem), and wound up with a destroyed terminator in, perhaps, 2020.  Someone like Cyberdyne, or like the USAF-CRS-AWD, got those parts and started researching, launching Skynet a couple years later, perhaps in 2025, and by 2029 the new Skynet had its time machine and was losing to someone named Conner, and so sent a terminator back to kill Sarah, starting the histories we know.

That gives us a distant future original launch date which is erased by the more recent one.  It is likely that it will ultimately result in a catastrophe (because given the massive changes made by the earlier launch of Skynet, the odds are fairly weak that that future Skynet will decide to target the same person in 2020, and that causes the entire timeline to collapse), but it gives us breathing space for the present situation.

The new film gives us several new trips to the past, but also interacts with all the old ones.  We count the arrival of Pops in 1973 and of a T-1000 that same year; we have the 1984 presence of a T-1000 to kill Kyle; we have the arrival of what some have identified as a T-5000 in 2032 to compromise John; and we have John's arrival in 2014 to safeguard the 2017 launch of Skynet.

We have already suggested that the only way nine-year-old Sarah can survive the pursuit of a T-1000 in 1973 is if Pops is already there, and that means that Pops must leave before the 1973 T-1000, sent prophylactically to protect her against any possible attack; that is also confirmed by the notion that Skynet cannot know when/where Sarah is until the resistance reveals it by sending Pops, and therefore that T-1000 must have been sent temporally after Pops.

Since once John is compromised everything changes completely, it must be that his trip is the last sequentially; that is, it happens after the T-5000 leaves from the distant future.  That trip has to be the last chronologically, which makes it the penultimate sequentially, as once it occurs John's trip is inevitable.

There are only two ways Pops can know about the T-1000 sent for Kyle.

Pops could have known that the T-1000 was going to arrive to kill Kyle in 1984 if it was sent before he was.  That unfortunately means that Sarah and Kyle in 1985 have to escape both the T-800 sent to kill her and the T-1000 sent to kill him, and (to preserve the timelines) must manage to conceive John and leave pieces of the T-800 in the Cyberdyne factory while destroying the T-1000 completely.  That also seems unlikely, given that Sarah barely survived the T-800, Kyle was killed in that fight, and the T-1000 was a far more challenging adversary which the T-800 could barely defeat in the second film--not to mention that Kyle knows nothing about T-1000s but what Sarah tells him, and Sarah knows only what she learned from Pops.  So if the T-1000 is sent first, Kyle is dead, and Sarah is also dead, in 1984.  John is never born, and nothing is ever sent to the past, and we collapse into an infinity loop.

If the T-1000 had not been sent from the future before Pops was, then it must be that after Pops arrives in the past, Sarah and Pops became aware of the arrival of a T-1000 pursuing Kyle, managed to save him from it, passed that information to John, who passed it to whomever sent Pops, who passed it to Pops to take to the past.  They had to do this the first time without advance notice that the T-1000 was coming, and thus without creating the effective trap for it, and this complicated game of telephone (in which the information is passed from one person to the next) has to work with minimal distortion of the message.  That is very doubtful, but not as problematic as the alternative.  Thus we conclude that Pops is sent next, because he has to be sent before any one of the other four.

It almost does not matter which T-1000 is sent to the past first, the one arriving in 1973 (to kill Sarah) or the one arriving in 1984 (to kill Kyle).  Yet there is an important point in the reconstruction of the seventh altered history that impacts this:  if Sarah is going to save Kyle from the T-1000 in 1984, she must have Pops' help both to stop the T-800 coming for her and to escape the unanticipated attacker after Kyle.  Therefore there has to have been something that caused Sarah to meet Pops before 1984, and to trust him, and the obvious answer is that in the next history the T-1000 arrives in 1973, and Pops saves Sarah's life.

That also fits with our suggestion that Skynet learned where Sarah was in 1973 (something it did not know when it sent the T-800 to 1984) from the fact that Pops was sent there.  That suggests that sending Pops was a mistake--except that Skynet will undoubtedly learn that Kyle was sent to 1984 from independent sources, and if it can kill Kyle in 1984 with a T-1000, it eliminates John and wins the war.

This is also the most complicated timeline, first because of what we do not know, and second because of what we do know.

The first piece is obvious.  Pops arrived in the past in or about 1973, and was watching Sarah when a T-1000 arrived, destroyed the cabin killing Sarah's mother, disguised itself either in or as the boat, and killed Sarah's father.  Pops moved into action, rescuing Sarah and getting her to safety.

That makes it sound so simple.  He simply got her to safety.  Where?  How?  These things never stop, remember?  Oh, but it's been a few years that T-1000s have been around, and by now the resistance knows how to destroy them.  Good thought, but with two problems.  One is that Pops could not have brought back any futuristic weaponry so if there is a future weapon that reliably destroys T-1000s, he does not have it.  The other is that if there were a simple way to stop T-1000s, they went to an awful lot of trouble to build and execute a trap for the one pursuing Kyle, when they apparently had plenty of time to prepare and could have stopped it the same way they stopped the one pursuing Sarah.

It is not impossible that they never destroyed that T-1000.  It might be that its mission was to kill Sarah Conner, but if it lost her it should intercept Kyle Reese in Los Angeles in 1984.  This simplifies things quite a bit; in fact, it removes another problem entirely.  The difficult part is that the T-1000 then has most of eleven years to find and kill Sarah Conner and despite its advantages fails to do so.  Yet we are never told that Pops destroyed the 1973 T-1000, and we are clearly told that Sarah completely vanished from the grid such that there was no record of her existence after that time.

However, this does not resolve the matter so easily.  The problem is what Sarah "knows" about the future.  She wants to stop the launch of Skynet in 1997.  The only way she can have that date is if Pops provided it.  However, that date can only be correct in timelines in which the T-800 and Kyle both came to 1984 but the T-800 never came to 1996 (whether or not the T-1000 did).  Once the T-800 comes to 1996, Sarah destroys Cyberdyne's research, preventing the 1997 Skynet launch.

The best guess at a solution here is that whoever sent Pops back to protect Sarah did exactly the same thing John did for the T-800 in 1997:  programmed it with information based on the history that was erased.  However, this just became incredibly more difficult.  By the time anyone might have thought to send Pops back to protect Sarah--

• The 1997 launch never happened;
• John Conner is dead, and cannot pass information to anyone.

On the other hand, Kate is still a factor at this point.  She might have sent the T-800 to protect Sarah.  We know that she was present when John reprogrammed and sent the 1996 T-800, and that she herself reprogrammed and sent the 2004 T-800, so she is the perfect candidate for sending Pops, and she would have known the history with which John programmed the 1996 T-800 and probably why he sent false information about the launch date of Skynet to his mother.  It makes perfect sense for her to have done the same thing.

In Watchmen we encountered a character who seemed to live in multiple realities, and noted that the absurdity and impossibility of this went well beyond the problems of Schroedinger's Cat.  Yet something similar to this seems to be happening here.

Complicating it, while he is in transit he experiences memories of yet a different history--one that he has yet to create and that is caught in a predestination paradox.  Kyle will tell Sarah that they have to go to 2017 to stop Skynet which is Genisys.  He knows this because when he was a boy, in that other history of the world he never experienced, someone told him this.  Then when he is in 2017 and has stopped Skynet such that he will never make the trip from 2029 to 1984 or the subsequent trip from 1984 to 2017, he delivers that message to himself so that he will know it.

Fixed time advocates will argue that it is perfectly possible for such a causal loop to exist, as long as all the causes and effects are included in history.  This is not a fixed time story; history has been changed multiple times, and this particular loop is one of the major causes of the change.  Even if it were so, one must look at the uncaused cause in a reverse way:  if Kyle never travels to 2017, he will never give himself the message; if he never gives himself the message, he will never receive the message; if he never receives the message he will never travel to 2017.  Thus if Kyle does not travel to 2017 he will not travel to 2017, and anything that will not happen unless it happens will never happen.  That is quite apart from the complication that the Kyle who gives the message comes from a universe that has been erased, and the Kyle who receives it from a universe in which John Conner was never born.

That pushes us toward two more problems.

The first of those problems is that Sarah never has a child in 1985.

This is a serious problem.  Remember, the reason Skynet sent the T-800 to 1984 is that it wanted to find and kill someone named Sarah Conner before she gives birth to John Conner, leader of the resistance.  John is not born (nor any other Conner child).  That means no T-800 will be sent to 1984 to kill someone who does not matter.

Further, Kyle Reese was sent to 1984 to protect Sarah from that T-800, and if the T-800 is never sent he will never be sent either.

It is more complicated than merely that Kyle won't father John.  There will not be T-800 parts for Cyberdyne to use to jumpstart the Skynet research in 1984 for the 1997 start.  However, Sarah and Pops needed a processor chip from a terminator to operate their time travel machine.  They got one from the T-800 that was sent to kill Sarah.  Without John's birth in 1985, Sarah never gets the chip she needs in 1984.  Besides, if she did get it, she would have gone to 1997, twenty years too soon for the inexplicable delay to 2017.

Of course, it's not quite as simple as that.  There is a timeline in which the T-800 and Kyle Reese are both sent back, and then after that Pops is sent to an earlier time.  In that timeline the departures of the T-800 and Kyle Reese have not yet been undone, so they could arrive in the altered history--but when that history reaches 2029 their departures are undone, and history reverts to the moments at which they now do not arrive, and long before Pops is sent to the past Sarah has no processor for her time machine and no father for her child.  That will certainly confuse events, as Pops is expecting these travelers from the future who now never arrive.  It pretty much undoes any chance they had of saving the world.

In the end, in 2017 Kyle and Sarah do get together, and we expect them to live happily ever after.  This is just one of several bits pointing to a sequel (the upgrade of Pops to include poly-alloy mimetics and the survival of the Skynet core somewhere under the Cyberdyne rubble are the big ones):  Sarah and Kyle will, we suppose, give birth to John (who should then be John Reese, and won't that confuse the issue further--but this is California, where it is legal to give a child any name you wish as long as it is not in furtherance of an act of fraud) and the writers will be able to delay the launch of Skynet to another near-future year and still have a John Conner (Reese) to be the warrior.  Quite apart from the issues we saw in About Time (the Genetic problem concerning what happens if the circumstances surrounding the conception of a child are altered the slightest bit), any such child is born much too late to matter to Skynet:  without the Connors interfering, it will have launched long before now.  If John is not born on schedule, he becomes inconsequential, and the notion of pushing back the Skynet launch and moving his own birth later falls apart.

The other problem is just as bad.

Once upon a time Sarah Conner was an ordinary person living an ordinary life on the grid in Los Angeles.  She was not exactly simple to find--the terminator killed a couple of others before her--but she was in the phone book and she was known to be in Los Angeles at this time.

That all changed when a T-800 saved a nine-year-old Sarah from a T-1000 in 1973.  She is so off-the-grid that in 2017 they have no record of her existence.  She was that unknown in 1984.  You can bet that there's no phone listing, no computer records, nothing since she dropped out of school and vanished when her parents were killed at their cabin on the lake a decade earlier.

That means that there is nothing to indicate that she was ever in Los Angeles.

That means Skynet can't target her there.

Again we have the existence of an intermediate timeline, one in which some of the changes have happened and others have not; but it is an unstable timeline, and when 2029 arrives no one is going to be sent to 1984 because no one knows that Sarah is there.  It is exactly the same problem that was created when John was never born.  We are seeing a lot of exciting scenes which might have happened, but only in histories of the world that are erased and replaced.  If Sarah is not on the grid, Skynet cannot target her, and the arrival of a T-800, and of Kyle Reese, in 1984 is artifact of a future that is being undone.

By this point you are probably as confused as I am, and the only way we are going to resolve this is to go back to the beginning before the beginning:  in the summer of 1973, Sarah Conner is at the cabin at Big Bear Lake.  That is now our starting point, not for the first anomaly but for several others that become entangled with it eventually.

Almost certainly on May 12, 1984 Sarah meets someone in Los Angeles and becomes pregnant; we know nothing else about that relationship but that she has a child prior to 1997.  Of this child we know only that it will eventually become a problem for Skynet, and that it is born probably in the early winter of 1985 probably in Los Angeles.

In or about 1994, Sarah Conner is diagnosed with cancer; she dies three years later in 1997.  This might not happen, but we know that it happens in a later history, and have no reason to suppose it does not happen in this one.

In or about 2004, a virus crashes the Internet.  There is no effective response.

Someone named Kyle Reese is born sometime in the early aughts.  We know very little about him.

Sometime after 2017 but well before 2029, perhaps around 2020, an artificial intelligence seizes power and begins destroying humanity.

Sarah Conner's child survives and becomes a significant leader in the resistance.

In 2029 Skynet is losing, and on an unspecified date that year activates its experimental time machine to send a Terminator back to May 12, 1984, creating a new history.

Everything from the original history happens as given up to May 12, 1984.  On that date, a Terminator arrives from 2029 programmed to kill Sarah Conner, in order to prevent the birth of her child.  It is not the T-800 we see in the film, which has not yet been developed, but an inferior infiltration model.  Sarah meets the father of her child and avoids being killed by the Terminator long enough to recognize that it is seeking her and to flee.  She gives birth to the child somewhere away from Los Angeles in early winter 1985, but eventually the Terminator catches and kills her, then shuts down, its mission complete.  The child survives.

Again a virus crashes the Internet in 2004, and someone named Kyle Reese is born probably in October after the war begins.  Again Skynet launches around 2020.  Sarah Conner's child again becomes a significant leader in the resistance; it is probably a boy named John.

In 2029 Skynet again sends the same Terminator model to the same date, confirming this first altered history.

A few hours later, Sarah Conner's child selects someone to send to protect Sarah.  That selected individual is named Kyle Reese.  He travels back to May 12, 1984, not long after the arrival of the Terminator, creating another new history.

The inferior terminator which created the first altered history is already seeking Sarah Conner when Kyle Reese arrives late on May 12, 1984.  Since Kyle knows more about Sarah than the terminator does, he immediately locates her, and incidentally interferes with her meeting with the father of her child.  He rescues her from the terminator and explains to her what is happening, but this time before they can escape the city he becomes the father of her child, leads the terminator to the Cyberdyne factory, and is killed by it while protecting her.  It is destroyed there, giving Cyberdyne pieces it never admits to having.

The Conner child is born in early winter 1985; it is a boy named John.

Sarah survives and raises John for a while, telling him about Kyle Reese and what she knows about the future war.  She does not know the date.  She is ultimately hospitalized as delusional.  She is diagnosed with cancer and treated (as a mental patient she would probably have been ruled incompetent to make her own medical decisions and so treated without her consent), and so she is still alive but hospitalized in 1997.

Cyberdyne studies the pieces of the terminator found in its machinery, and starts developing a superior technology.  They develop a software/hardware system called Skynet, which launches on or about August 4, 1997, and on or about August 29, 1997 it responds to efforts to deactivate it by launching a nuclear attack and beginning the eradication of humanity.

Because of the Cyberdyne connection, Skynet now has a hardware component that functions from a central core.  Sometime in 2029 the resistance has discovered this core and destroys it, but Skynet is already sending a terminator to the past.  This is a superior terminator, because Skynet has the benefit of Cyberdyne's examination of the previous terminator parts in creating a more advanced system sooner.  Because this is not the same terminator, it changes history.

Again a terminator arrives on May 12, 1984; this is a superior model to the one that arrived in the first and second altered histories.

Kyle Reese having already been sent arrives hours after this terminator and again manages to save Sarah, father John, and get killed; Sarah manages again to destroy the terminator in the Cyberdyne facility, and Cyberdyne takes over the parts to begin work on Skynet.

Because the parts are superior to those in the previous history, Skynet is superior, and the terminators it develops are superior; however, the launch date will stay pretty close to the same time in 1997, there will still be a central core, and in 2029 Skynet will again send a further improved terminator back to 1984.

This history will repeat with an escalating terminator until it becomes the T-800 model 101, at which point history stabilizes as Cyberdyne cannot learn more from the parts of the new model than they could from the previous incarnation.  Kyle always fathers John and gets killed saving Sarah, leaving terminator parts at Cyberdyne.

Once the sawtooth snap stabilizes and the T-800 is the model sent back, history again reaches the point at which Kyle Reese is sent to the past.  This version, though, now knows more--he knows more about the T-800.  He prepares Sarah to prepare John, fathers John, dies, and leaves T-800 parts in the past for Cyberdyne to study.

John is born.  Sarah is hospitalized.

Again Skynet goes online in August, 1997, and begins destroying humanity.

Again someone named Kyle Reese is born, and because John Conner knows that his father is Kyle Reese, John assumes this Kyle Reese is his father and sends him back to protect his mother.  The second history stabilizes, and time continues for an unknown number of months, probably not a year, to the moment when Skynet manages to complete the T-1000 and send it to kill a young John Conner, creating the next history.

Sometime between 2029 and 2032, probably early 2030, Skynet decides to send its newly-developed T-1000 back to kill the young John Conner, to a very unspecified date, which according to our calculations must be not later than 1994 but not earlier than 1997.  Yes, that's correct--the earliest possible date is later than the latest possible date.  For convenience, we overlook this discrepancy and choose 1996 as the target year.

At this point the history has included Sarah's visit to Bear Lake in 1973, the arrival of a T-800 and of Kyle Reese in 1984, the birth of John Conner and his early education, and the incarceration of Sarah Conner in a secure mental facility.  The new history diverges from this in or about 1996 with the arrival of the T-1000.

The T-1000's mission is to kill John Conner; its fallback is to capture Sarah Conner to use as bait, but ultimately it will kill her.  It tracks John to the mall, but ultimately John manages to evade and escape, so it takes Sarah, and kills her, but then one of two things happen.  The less likely is that it reveals itself sufficiently that forces are mobilized that are sufficient to stop it, and it is destroyed without completing its mission.  The more likely is that it continues searching for John Conner in the city until, in August 1997, judgment day comes and it is destroyed in the nuclear attack.

Someone named Kyle Reese is again born sometime after 1997, who is probably a different person with the same name.  History continues through the 2029 sending of the T-800 and of Kyle Reese to early 2030, when the same T-1000 is sent on the same mission.  This timeline stabilizes and history advances a matter of a few hours or less, at which point John Conner sends a repurposed T-800 and creates the next history.

Sometime again in what is probably early 2030, hours or possibly mere minutes after the T-1000 has been sent to kill John but has only succeeded in killing Sarah, John sends a reprogrammed T-800 back.  His motivation for doing so is to save Sarah, but he recognizes the danger that in saving Sarah he might end his own life, so he programs it to protect and obey his younger self, hoping that his younger self will take the steps to save Sarah.  This actually works, but the incidental consequences are significant.

History again is rewritten from that uncertain date which we have made 1996 despite the impossibilities.  The T-1000 is already here looking for John Conner, but John knows that it found him at the mall, so it sends the T-800 there and manages to rescue himself.  From there he rescues Sarah, so that she is not killed, but this puts the T-1000 on their trail.  They manage to destroy it.

At that point, Sarah obtains as much information as she can from the T-800 concerning the origin of Skynet, and proceeds to pursue a plan to destroy it.  All of Cyberdyne's research and the parts of the old T-800 are demolished, and lead engineer Miles Dyson dies in the process.

Skynet does not go online in 1997.  Fortunately, the T-1000 was destroyed by the Conners and the T-800, so the fact that it is not destroyed in the nuclear attack does not matter.

In 2003, Marcus Wright is convicted of murder and agrees to give his body to Cyberdyne for research.  He is put in some kind of suspended animation.

In 2004, John Conner has a motorcycle accident and breaks into a veterinary hospital to obtain some medical supplies.  While he is there, Kate Brewster arrives.  They begin to get re-acquainted and probably go out to breakfast together.  A virus begins crashing the Internet.  When systems begin failing, the paranoid John begs Kate to take him as far from the city as possible.  The United States Air Force Cyber Research Systems Autonomous Weapons Division launches an antivirus program developed from Cyberdyne's preserved research.  It interfaces with the virus, becomes Skynet, and launches the attack.  Thus when the bombs fall Kate is with John.  Scott is killed; General Robert Brewster is killed.  Skynet begins the systematic extermination of humanity.

Someone named Kyle Reese is born about this time.

In about 2018 Marcus Wright is activated.  Skynet determines that John is looking for someone named Kyle Reese, and attempts to use that as bait.  Working with Marcus Wright, John saves Kyle. Because he has that name, John Conner identifies Kyle as his own father, and supports him in the resistance.

In 2029, there is no central core, but the resistance is again winning.  Skynet sends the T-800 and John sends Kyle.  Kyle knows nothing of the T-1000, and does not know when the bombs fell.

In about early 2030 Skynet sends the T-1000.  John realizes that if he sends his mother the information that Skynet was created by the Autonomous Weapons Division of the Air Force and launched in 2004, she will not attack Cyberdyne, and Cyberdyne will probably launch Skynet early.  Thus he programs a T-800 with the history of the world that he heard the T-800 explain to his mother in 1996, and sends it back on a mission ostensibly to protect himself but intending to save his mother.  Sarah is saved, gets the now false information from the T-800, destroys Cyberdyne, and our history stabilizes.  We can move forward.

Everything is established through John Conner's motorcycle accident, with Skynet expected to launch in 2004.  Unable to locate John in the past, in 2032 Skynet sends a terminator back to kill his top supporters, including his wife Kate Brewster.  It arrives in 2004, on the day of the motorcycle accident, and within about a day before the launch of Skynet.

This is an ordinary terminator, probably a T-1000, possibly a T-800 or some other model not familiar to us.  It arrives at the veterinary hospital where it expects to find Kate Brewster, and kills a female.  It does not have the DNA testing trick, so it assumes this is Kate, and leaves.  Kate, meanwhile, is in the back talking to John Conner.  The police will be called, but John will hide so as not to be identified and located in a computer database.  His paranoia will probably suggest to him that this was a terminator, but his rational side will tell him that he is probably overreacting--after all, Kate says junkies often break in seeking narcotics, and this probably was simply a robbery gone wrong.  They will get breakfast a bit later, but then when systems start crashing he persuades her (with even more urgency, given the death that morning) to take him away from the city, and again they survive and become leaders in the resistance.  The terminator fails actually to kill any of the persons on the list of John's lieutenants, but General Brewster dies in the nuclear attack.

Someone named Kyle Reese is born about this time.

Marcus Wright is activated in 2018, and John finds and rescues Kyle with Marcus' help.

In 2029 the resistance is winning (although there is no central core), Skynet sends the T-800, John sends Kyle.  In 2030 Skynet again sends the T-1000 and John sends the T-800.  In 2032, Skynet sends a terminator, and history stabilizes.  John Conner is killed by a T-800 either shortly before or immediately after this event, and Kate Brewster captures it.  She reprograms it and sends it back with a mission to protect everyone on the target list, including herself and John.  She probably does this with the hope that she will be able to save her father, General Brewster.

Shortly after the unspecified model terminator arrives, the T-800 arrives.  It interferes and rescues Kate and John.  John learns that General Brewster is about to launch Skynet to stop the Internet virus that is crashing the systems, so he and Kate head there, but arrive too late.  General Brewster probably is killed, but probably sends John (whom he mistakenly believes to be Scott) and Kate to the bunker, where they survive the blast.

They emerge a few years later and join the resistance.  Marcus Wright is activated in 2018, Kyle Reese is used as bait but rescued, in 2029 a T-800 is sent to 1984 followed by Kyle, and early the next year a T-1000 is sent followed by a T-800.

In 2032, Skynet is aware that the terminator it sent to 2004 failed because there was another terminator present.  Instead of sending whatever terminator it sent in the previous timeline it sends a newly developed T-X "anti-terminator terminator", intent on killing a list of people including Kate and Robert Brewster and, if possible, John Conner.  Fortunately the T-800 sent by Kate also arrives, and manages to save them and destroy the T-X.  General Brewster is killed but sends them to the bunker, where they hide for a few years and emerge to lead the resistance.

In 2018 Marcus Wright emerges and Skynet uses Kyle Reese as bait, but John rescues him.  In 2029 the T-800 goes back followed by Kyle, and the next year the T-1000 and T-800 are sent back in their turns.  In 2032 the T-X is again sent, stabilizing the fifth history and permitting it to advance to the moment when the T-800 is sent to the past, stabilizing the sixth altered history and permitting time to advance.

We understand the eighth altered history.  A T-1000 arrives to kill Sarah Conner, and kills both her parents, but Pops had arrived already, emerges from hiding, saves her, and becomes her guardian as they drop off the grid and live in the shadows.  The problem is, how does the Pops become Sarah's friend and protector in that seventh history in which he arrived but the T-1000 did not?  Indeed, it must have been intended that he would protect her in that history, because we have already established that she could not have survived the T-1000 without him so he had to arrive in a timeline in which the T-1000 (not yet having been sent) had not arrived.  So perhaps he stays in the background, watching to prevent anything from happening.  However, he is going to have to stay very close--he cannot identify a T-1000 until it does something inhuman within his view--and that means from time to time he is probably going to be seen (as he says, he lacks the polymimetic abilities to look like someone else).  At some point, someone is going to wonder why this frighteningly muscular young man is constantly hanging around near this teenage girl.  How does he explain himself?  Does he contact the family before they contact the police, and tell them that he is a robot from the future sent to protect their daughter, who is likely to be targeted by a crazed world-dominating computer in that future because she is the mother of humanity's last best hope?

On the other hand, there is no reason to think Sarah is in any danger in this timeline until the arrival of the T-800 in 1984, and Pops' mission includes ensuring that Sarah Conner and Kyle Reese "mate" to produce John Conner--something that he knows will happen if he does not interfere (and that Kyle will be killed after it happens).  Therefore, the best policy for Pops in this history is to remain unseen as much as possible, at least until Sarah is pregnant and Kyle is dead, and probably thereafter--there is no reason for it to interfere in rescuing Sarah from the mental hospital, or protecting John from the T-1000, or becoming involved later in 2004, because these events will occur as they did as long as no one interferes.  His presence in this timeline is dependent on it playing through to the moment of his departure without alteration, so it makes perfect sense for him not to alter it.  He might have arrived years earlier, say in 1964 when Sarah was born, and was watching all along--except that if he arrived near Sarah in 1973, it explains how Skynet targeted her.

So this timeline plays out very like the previous one, with the 1984 arrivals of the T-800 and Kyle, the 1996 arrivals of the T-1000 and the T-800, the destruction of Cyberdyne, Sarah dying shortly the Judgment Day date she was given in 1997, John disappearing and meeting Kate in 2004, the 2004 launch of Skynet, the rise of John and Kate in the resistance, the 2029 sending of the T-800 followed by Kyle, the 2030 sending of the T-1000 followed by the T-800, the 2032 death of John, sending of the T-X, and sending of the T-800, and then the sending of Pops, which we will place in 2033 simply for convenience, confirming and stabilizing this history.

Whew, we made it.  But it gets worse.

Pops arrived in 1973, and when the T-1000 appeared he rescued Sarah, took her off the grid, and started preparing her for the war.

When we reach 1984, Sarah and Pops are waiting for the T-800 and for Kyle Reese.  They also know that there is another T-1000 out there, because they have been evading it for eleven years--but they might have anticipated that it would attempt to catch them in Los Angeles because if it knows that Kyle Reese is going there, it probably knows that they have to meet him there.  They have two reasons to ambush the T-800 that comes for Sarah.  The first is obvious--it is there to kill Sarah, and if they can kill it first without all the trouble of the previous histories, they have an advantage.  The second is the time machine.

Before they head for their time machine, though, they go to get Kyle--and find that he is trying to escape the T-1000.  They manage to get him out of there and lure the T-1000 into the trap they built--after all, with a T-1000 after you for over a decade, you're going to have time to think about how to eliminate it if you get the chance, and to prepare whatever you think will make it work.  They lure it into their trap, destroy it, and then turn their attention to their time machine.

They needed to destroy the T-800 because they needed its central processing unit to control the time machine.  Pops has told Sarah that judgment day comes August 29th, 1997, and she is intent on stopping it by going to 1997.  Here, though, the story falls apart in so many ways.

Sarah has learned from Pops that Skynet goes live in 1997, and she has decided to go to 1997 to stop it.  She does not realize that she has already stopped it--Cyberdyne does not have the parts from the T-800 that came to kill her, so it will not be able to produce the advanced technology needed to create Skynet by that date.  If she goes to 1997, there's not much happening then, although there's another problem we'll reach in a moment.

Perhaps Kyle will tell her that 1997 is the wrong date.  However, that does not work--the stability of previous histories depends on the fact that Kyle does not actually know what year the disaster happened, so that he can't tell Sarah different years on different trips as the date changes.  Yes, but when he traveled to the past, didn't he see the events of the other history, in which the date is 2017?  We have already addressed that, but even if we accept the completely illogical premises, first, that the compromising of John Conner by the T-5000 was some kind of "nexus point", and second, that this made it possible for Kyle to see a history that had not yet happened, this Kyle did not come from that history--the T-5000 has not yet left the future and therefore has not yet arrived in 2029, and this is the Kyle who left from the history in which 1997 is the date (because there is a central core, which only exists in those histories in which Cyberdyne launches a version of Skynet in 1997).  So there is no way Kyle can suggest a different date.

Further, it is obvious that they can travel through time--nothing will be different in any other history, they have had the time and means to build the machine, and have captured a processor chip to operate it, and in the movie we establish that the time machine works--so they are going to go to 1997.

That introduces the fundamentally critical problem:  Sarah Conner will not have a child in 1985.  She won't even exist in 1985, because she is leaping from 1984 to 1997.  She is taking Kyle with her, and perhaps once they see that there is no Skynet launch in 1997 they will relax and have children before the 2004 launch date, but this changes everything.

However, it does not change everything yet.  The T-1000 that pursued them from 1973 until they destroyed it in 1984 was sent from, we guess, 2033, and so this history keeps advancing to 2033 before we find out what happens next.  The events of the previous history that are still in the future from 1984 have not yet been erased, even though they are being erased and replaced.  That means in 1996 a T-1000 which left from 2030 to kill John Conner arrives, and a T-800 which came moments later to protect John Conner also arrives, but there is no John Conner.  These time travelers arrive because their departures have not yet been erased.  We have no idea what they are likely to do.

Well, not exactly no idea.  The T-1000 will begin looking for anyone who knows the non-existent John Conner; the T-800 will obtain guns and go to the mall to rescue him.  Unable to locate any trace of John, the T-1000 will move to the fallback plan and go to the mental hospital, where it will probably kill a lot of people trying to find the woman who has not existed for eight years and was off the grid entirely for eleven years before that.  The T-800, meanwhile, will begin searching for John.  It has no need to confront the T-1000 or stop its killing if John is not endangered.  Pops is there somewhere, gathering information and awaiting the arrival of Sarah and Kyle in 1997 (he could not use the time machine because of the exposed metal in his hand), but there is no reason for him to interfere, either.

Then in 1997 Sarah and Kyle arrive from the past.  They are intent on preventing a Skynet launch that they have already prevented.  Pops has nothing to report--but there is a T-1000 out there looking for John and Sarah Conner, and if it gets wind of her presence, she, Kyle, and Pops will have to destroy another T-1000, probably without any advance warning.

We do not know what will happen, but there is a degree to which it does not matter.  Eventually Skynet will launch.  Whichever future visitors are still existent in the past will be as likely to be destroyed as anyone else.  Skynet begins destroying the world, but there is no John Conner in the resistance.  Kyle Reese is born, but he is no one of consequence even if he lives long enough to join the resistance.  We do not know whether the resistance will be able to survive without John, but it again does not matter.

In 2029, whatever else happens, one thing does not happen:  Skynet does not send a T-800 to 1984 to kill Sarah Conner, because Sarah Conner is nobody.  Boy, does this confuse things, though, because that was the lynchpin of everything, and there is a string of trips to the past that have to be resolved.

We just erased the original trip to the past, when a T-800 travels from 2029 to 1984, and so we have to go back to 1984 to rewrite history.  However, we did not erase any of the later departures, and thus we have all the other arrivals.  That means Pops has been with Sarah since 1973, when a T-1000 killed her parents and she vanished, and that the T-1000 is right now awaiting Kyle's arrival.  Sarah and Pops will wait for the T-800, but when it does not arrive, eventually they will drive across town to find Kyle.

The schedule is disrupted:  because there was no T-800, their actions are altered.  This means they did not reach Kyle at the same time.  They might be too late, in which case he is dead (and Officer O'Brian is probably also dead).  They are less likely to be early, but if they are they rescue Kyle that much sooner.  They lead the T-1000 to their trap and spring it, and then discuss their problem.

The problem is that they have a time machine without a controller processor chip.  It is beyond unlikely that they would be able to salvage the one from the T-1000--trying to destroy it and preserve the chip would be a much more challenging task.  Sarah will not be willing to sacrifice Pops to make the trip.  They are stuck in 1984, or as stuck as everyone else; they'll have to live through the next thirteen years to be able to do anything in 1997.

Pops, of course, will be focused on getting them to "mate" so that they can produce the child that will be John.  That's probably not too much of a problem for Kyle, who has been in love with his image of John Conner's mother for years; Sarah, meanwhile, has been raised to believe it is her inevitable fate, no matter how hard she pushes against it--and it's a complicated situation, because it is obvious the future has changed when the T-800 (which both Pops and Kyle expected would be here) never arrived.  However, one of three things (possible and relevant) happens:  either Sarah has a child by Kyle, or Kyle leaves and Sarah has a child by someone else, or Sarah has no child.

• If Sarah has no child, we go through 1996 events similar to those of the previous version, in which the T-1000 is looking to kill and the T-800 looking to protect Sarah Conner's non-existent child.  This time Sarah does exist, but she is not in the hospital (she never attacked Cyberdyne).  Again, whether or not she and/or Kyle survive is not that important; in 2004 the T-X and T-800 arrive but there is no John.  Kyle is born, joins a resistance in which there is no John Conner, and in 2029 no Terminator is sent to kill an insignificant woman, and that history stabilizes and advances to the moment that Kyle Reese is not sent to the past to protect her.

  This again shifts the past, because now after not finding the T-800, Sarah and Pops race across town and never find Kyle Reese.  Perhaps they never know whether he arrived and was killed or simply never arrived--but they encounter the T-1000 that was sent to kill him, and lead it into their trap.  Again they have no processor chip, but this time there is no Kyle to father the baby, and with Sarah and Pops staying below the radar she probably is not gong to have a child in this history if she did not have one in the previous one.  Time again progresses through the arrivals of the T-1000 and T-800, who again have no John Conner for their missions.  This history will thus be similar to the previous one, without Kyle, Sarah has no child, 2029 sees no one sent to the past, and in 2030 the T-1000 is not sent.  History changes yet again, this time from 1996 forward because there is no T-1000 there to kill John, so Sarah probably survives long enough to, we presume, die of cancer (she might survive--we do not know whether in her altered life she would have succumbed to cancer), or else live some uncertain length of time.

  Similarly in 2032 John Conner, who never existed, is not killed, and no T-X is sent back to kill Kate.  Once that history stabilizes, Kate is not there to send a T-800 back to protect herself, so that does not happen.

  Regardless of who was responsible for sending Pops to the past, that is the next event that does not happen, and since undoing the sending of Pops means he is not there to protect Sarah from the T-1000 already sent, Sarah dies in 1973, and again everything changes.  None of the terminators arrive between 1973 and 2004, and none are sent between 2004 and the sending of the T-1000 to 1973, and since Sarah is an inconsequential nobody who died mysteriously in 1973, the T-1000 is not sent to the past.

  That puts us into a massive infinity loop because we have now restored the original history in which Sarah gets pregnant by some unidentified father in 1984, and has a child who becomes a problem for Skynet, and all of these histories repeat the same way perpetually.

• If Sarah has a child by someone who is not Kyle, that child will probably become the replacement for John Conner.  There's a 51% chance that any random child would be a boy, and if so she will probably name it John; she and Pops will raise it to be aware of the coming war, and it will be the more aware because of the proof that is Pops.  Sarah is not in the mental hospital because she was not attacked at Cyberdyne, but in 1996 a T-1000 arrives to kill John and a T-800 arrives to protect him.  There is some reason to believe that Pops will anticipate these arrivals (they existed in the history from which he was sent) and thus working with the T-800 will evade and destroy the T-1000 more easily, probably by building another similar trap.  There is also considerably less reason to destroy the newer T-800, already reprogrammed to protect John.  They might use the chip from the T-800 for their time machine, except it is almost 1997 and they are more likely to succeed in stopping Skynet by attacking Cyberdyne now--despite the fact that history has been altered and Cyberdyne does not have parts from the 1984 T-800.  Dyson knows nothing about her claims, but Sarah is a fanatic, having been attacked by a T-1000 as a girl, and will assume he is lying.  It does not matter whether they succeed; there is no 1997 imminent launch to abort.

  We do not know whether Sarah lives or dies at this point, but John has been prepared and probably has two T-800s protecting him.

  In 2004, the T-X and T-800 both arrive.  Since this version of Sarah Conner's child is not the John Conner fathered by Kyle Reese, we do not know whether he (or she) will be at the veterinary clinic to meet Kate Brewster.  However, it seems reasonably likely that Pops comes from a history in which Kate Brewster is John Conner's wife, so he is likely to attempt to arrange some kind of meeting before the 2004 launch, and probably very close to the intended date.  This would be a very confused situation, since there would now be three T-800s protecting them--one protecting Sarah since 1973, one sent to protect John in 1996, and one sent by Kate in 2032 to protect Kate in 2004.  Probably this version of John survives the war, probably with Kate and at least one or two of those three reprogrammed T-800s.

  As we reach 2029, we have a problem.  Certainly Skynet will send a T-800 back to kill Sarah Conner in 1984, but at this point we are pretty sure that's not going to happen--Sarah has Pops and knows it's coming, and they will destroy it.  That means John has no reason to send anything back to protect Sarah, who is not in any danger.  Further, his mother never told him anything about Kyle Reese, who was just a guy who came from the future to give her protection she did not need.  Kyle is not sent to the past, and our histories all unravel from there.

• That leaves the possibility that Sarah and Kyle have a child.  Odds are actually better than 51% that it will be a boy (long story, but there are some non-random factors in sex selection and for the same couple they are more likely to be the same than different); they will certainly name him John.  In 1996 the T-1000 arrives to kill and the T-800 to protect him, but they are ready for this and destroy the T-1000 and enlist the T-800.  Both Pops and the T-800 are programmed with the 1997 date, so they attack Cyberdyne.  Sarah probably dies, and we can't even guess about Kyle, but John gets better training and knows to rescue Kate from the T-X in 2004; they are joined by the T-800 that was sent to protect Kate.  Judgment Day is still over a decade away, but eventually arrives.  Since there is a John Conner who is a problem for Skynet, the 1984 T-800 is sent back in 2029; since John knows that Kyle is his father, he sends him back ostensibly to protect his mother whom he knows is going to be fine.  History stabilizes.

  The next year the T-1000 and T-800 are sent to 1996; there is no reason to believe that they are different in any way, and thus they will fall into the same history already established and we have N-jumps.  In 2032, a T-800 kills John, a T-X is sent to the past to kill Kate, and Kate sends the T-800 to protect herself even though John rescued her.  These histories all stabilize, and Judgment Day happens in July 2004.

History thus can now advance to the moment when Pops was sent to the past, and Kate is still alive to send him; then the T-1000 is sent to 1973, confirming the history to this point.  We still have a complete possible history, with a launch date for Skynet after 2017.

This gives us the issue of how the 2017 launch date was initiated, and the answer seems to be that Skynet sent something back probably to a date around 2014 to do something which resulted in launching itself earlier.  To get there, though, we will have to move forward.

However, forward seems to be a direction we cannot go.

The problem is simple.  At this point, if Skynet does not send a T-800 from 2029 to 1984, Sarah is stuck in 1984 and will probably give birth to the child that causes Skynet to send the terminator; if the terminator is sent, Sarah and Pops are awaiting it and destroy it, and then use the chip to leave 1984 probably for 1997--in which case Sarah does not have a child in 1985, and Skynet has no reason to send the terminator there.  As we have seen, the interaction of the timelines is much more complicated than that, but in simple terms, we are stuck in a complicated infinity loop.

Let us guess, though, that Sarah and Kyle leap forward to 1997, and find that judgment day does not happen.  Sarah has skipped to the date of her death, but she's not that old--she is thirteen years younger than she would have been.  Pops is waiting, and working with the 1996 T-800 they find a way to eliminate the 1996 T-1000.  They won, as far as they know.  Skynet will not go on line.

We don't know that Sarah connects with Kyle, but it seems at least plausible that she will connect with someone, and give birth to a child in 1998.  She is likely to name him John, maybe even John Conner; or maybe he will take his mother's name after the war begins.  By 2029 he is thirty-one years old--old enough that he could well have been a problem for Skynet.  (In the previous iteration, when he was born in 1985, he would have been forty-four by then.)  So given this scenario, there is still a reason for Skynet to want to kill Sarah Conner.

The problem, though, is why Skynet targets Los Angeles, 1984.  In the original history, it was because that was the earliest, possibly the only, moment at which Skynet knew where Sarah Conner was.  It is not even entirely clear how that was known, although it was probably because of birth records for her child in early 1985, possibly but less likely from employment or tax records from her waitressing job (because Skynet does not know her address).  Those no longer exist--Sarah Conner has been off the grid now since 1973.

We do not have a solution for that, but then, we don't know how Skynet knew she was there the first time so it's difficult to make guesses.  Everything hinges on that being discoverable in any timeline in which she has a child, so there must be some way it was discovered.

Still, we at this point must assume that everything works, as improbable as it has all become, so that all the trips are made to the past up through the T-1000 being sent to 1973 to kill Sarah.  In that history, Skynet must go online after 2017 but before 2029, John Conner must lead the resistance, and Kyle Reese must be born and join it.

But we have another problem.

In 2004, John Conner breaks into a veterinary clinic where he meets Kate Brewster just before the T-X arrives and starts the events that end with the 2004 launch of Skynet.  Doing the math, John is 19; Kate is almost certainly within a year of that, because she remembers making out with him as the first boy she ever kissed the day before the T-1000 arrived in what we make 1996.  Because of the events of the next few hours, they wind up in a bunker surviving the nuclear launch and emerge as husband and wife leaders of the rebellion.  Kate is responsible for sending the T-800 that protects them.

That has apparently been erased.  First, we know that by 2004, John Conner is not older than six or seven years.  Second, we know that the destruction of the T-800 in 1984 has apparently eliminated the Autonomous Weapons Systems program and delayed Skynet.  That means General Robert Brewster is doing something else.  It also means that Kate Brewster is going to marry Scott Petersen within a year or two, and not going to be wife of John Conner, thirteen years her junior.

That's a bigger problem than simply that the events of Terminator 3 are disrupted:  Kate is our prime candidate for someone to have sent Pops to the past, and if Pops is never sent everything collapses.  The departure of Pops happened before the departure of the 1973 T-1000, and that means that it is erased first, which means that his arrival is erased first--Pops will not be there in 1973 when the T-1000 arrives to kill Sarah, and without Pops, Sarah is pretty certainly dead.

Sarah's death in 1973 derails everything--Kyle will be killed by the T-1000 in 1984, but then those trips, too, will be erased; the 2004 trips will be erased; and then the T-1000 trip to 1973 will be erased.  Then since that trip was erased we have reset everything to the original history, and it all repeats, a massively complex infinity loop.

Of course, maybe Kate was not the one to send Pops to protect Sarah.  The problem is, moving John's birth to make him seven years younger changes so much that it becomes unlikely in the extreme that the same person who sent Pops in the original history will send him in the new history.  It is really only because we do not know who the sender was that we can pretend it doesn't matter.  It matters very much, and there is no way we can resolve it but to say that apparently someone in the future wanted John to be born and so protected Kate from an anticipated attack which he, or she, apparently precipitated by sending the protector.

As previously mentioned, someone somewhere on the Internet gave the label "T-5000" to whatever it was that grabbed John Conner as Kyle Reese was leaving from 2029.  There is no identification of that part in the published credits.  What we do know is that when Pops left the future, he was aware that Skynet was working on a model that would use nanites (nanobots) to rebuild a human into a machine.  That means that John is attacked by something from the future which did not exist when Pops was sent to the past.  We thus make this the last confirmed departure from the future, something beyond 2032 by enough that Pops and the 1973 T-1000 were both sent and then development on this "T-5000" was completed.

Its target is 2029, where moments after Kyle Reese is sent to the past, it attacks John Conner, and alters him so that he is now a new type of terminator.  It is unclear whether he is also a T-5000, or whether he is something different, but it is not that important to our analysis.  From this point forward, T-John works for Skynet.  That is going to change a lot of things that happen after 2029--but first, it is going to change some things that happen before 2029, because once the T-1000 has converted John, it sends T-John to the past.

Inexplicably, its target is apparently 2014.  That is the arrival time T-John reports in what is a later history, when his reason for being there is to ensure the successful launch of Skynet in 2017--which we argue is caused by his presence in 2014, and not the original launch date.

We are in the realm of best guesses, but it seems that something must have happened in 2014 which Skynet in the future thought was very important to protect--just as someone sent Pops to protect Sarah Conner in 1973 because she would matter to the existence of the resistance in the future, so too Skynet feared that it had a vulnerability, that if the resistance recognized the importance of this event and sent someone back to prevent it, it might never come into existence.  So it sent something back to protect whatever it was.  It is also highly likely that whatever this was happened at Cyberdyne.  Thus we extrapolate that once again Cyberdyne is responsible for the launch of something called Skynet, at some date after 2017, and that Skynet sent technology from the future to protect that launch with the result that the launch was accelerated to 2017.

The story is by now falling apart; it barely holds together.

• Since Sarah Conner and Pops destroyed the T-800 in 1984 and then traveled forward, no time travelers will come from the future to 1996, and there is no 1997 launch date.
• Since Sarah and Kyle Reese leapt forward to 1997 before having John Conner, he is too young to connect with Kate Brewster, and she drops out of the equation entirely.
• Since the Air Force received no data from Cyberdyne's examination of the 1984 T-800 parts, there is no Autonomous Weapons Division in 2004, General Robert Brewster is unimportant, and there is no Skynet launch then.  Most of his lieutenants are now different, so the 2004 mission of the T-X is meaningless, and will not happen.

However, departures after 2029 are not erased until after we get beyond the 2029 departure of T-John, and so the terminators all arrive on schedule and struggle with missions that do not fit expected circumstances.

Let's do a bit of math.

Sarah's age is a bit uncertain, because in Terminator 3 her memorial plaque lists her year of birth as 1959, but in this film we are told that she was nine years old in 1973--which means born in 1964.  This might be resolved if we guess that she instructed that the wrong year be put on the plaque so that Skynet would not be able to use it to identify her in the past.  We thus conclude that she was twenty (and not twenty-five) in 1984.

Kyle Reese has his thirteenth birthday in 2017, which means he was born in 2004.  That fits with his claim that he was born after the bombs fell, and also with the scene that suggests he was near the home in which his family lived in the altered history:  they had not yet left their home that early in the war.  In 2029 when John selects him to travel to the past he is twenty-five.

In 1984 they leap forward to 1997, and they have John, whom they raise to anticipate the war they hope they have averted.  They are, respectively, twenty (Sarah) and twenty-five (Kyle).  By 2014, they are probably relaxing.  Kyle is forty-two, Sarah thirty-seven, and their son John is probably not older than sixteen; there might be younger children in the family.  Nothing happens that year anyway, or at least, nothing of which they are aware.  Cyberdyne soon makes some discovery or innovation that will make a difference in the future, but it is unlikely they would realize it.  In 2017 again nothing significant happens--even if Genisys goes online, without T-John's tweaks it will not become Skynet any time soon.  By then Sarah is forty, Kyle forty-five, and John perhaps nineteen and considering getting out on his own.  It will be at least a year, maybe as many as ten years (2027 is about as late as we can imagine the war beginning and still have the climax in 2029).  There's a good chance that Sarah will die of cancer in this time--assuming an original birthdate of 1964 and a death by cancer in 1997, she was thirty-three when the cancer took her, and while her situation is different there is a genetic component to cancer which suggests she is at least susceptible to it.  Kyle did not have a particularly healthy childhood and might also die younger.  In short, whether Cyberdyne launched Skynet in 2018 or in 2027, no one had any knowledge of how to stop it.  John Conner, though, has been taught and prepared, and he rises to the task and becomes the resistance leader.

It is nearly impossible to reconstruct events from this point forward, as trips are erased, but in 2029 right after the T-800 and Kyle are sent to the past, the T-5000 compromises John creating our T-John, and shortly thereafter sends him to 2014.  The T-John who arrives in 2014 maintains a low profile--he does not permit Cyberdyne to give him any credit while he tweaks their systems.  There is no reason for Sarah or Kyle or Pops or John to realize he is there or take any steps to stop him, and as a result this time in 2017 Genisys goes on line and becomes Skynet.

That anomaly is relatively short--we can fully expect that Skynet, not knowing that the T-5000 is about to arrive to compromise John, would send the T-800 to 1984, and that John would send Kyle, whom he knows to be his father, to protect himself.  The T-5000 is waiting, and it comes from a timeline in which John has not made those changes so it does not know the changes were made.  It sends John to the same point in the past to accomplish the same mission, and John takes the same actions, so this history stabilizes.

We now have an incredible leap.  Somehow, Kyle Reese, born in a world in which all he knew was that the war had started before his 2004 birth, realizes in 1984 that the war will not start in 1997, nor in 2004, but long after his birth, in 2017.  He somehow knows that Genisys, whatever that is, is Skynet, and that if they stop Genisys they can stop Skynet, and the anticipated launch date is in 2017.

Every reason that has been suggested to explain how he can know that fails.  Yet somehow he must know that, or the movie fails.  That's fine--time travel movies fail all the time, and this one is so improbable at this point that it's collapsing under its own weight.  Yet it is necessary for Kyle Reese to argue with Sarah that 2017 is the right target year--and to do so without the memory of Sarah telling him the bit about going and not looking back, and without the benefit of his own message to his younger self, because those things did not happen in the history in which they did not arrive in 2017 from 1984.

It is absurdly improbable.  He cannot know, and even if he knew he could not persuade her.  Yet somehow he knows, and somehow he persuades her, and when they depart from 1984 their new destination is 2017.

At this point the movie can play through much as we see it.  Armed with the knowledge that something called Genisys becomes Skynet, Kyle, Sarah, and Pops mobilize, T-John attempts to stop them, and the good guys win.  Unfortunately, though, we have now moved into a major problem that is probably the death of the story.

Originally, Sarah Conner's child was born in 1985.  That made him twelve in 1997, nineteen in 2004, thirty-two in 2017, thirty-five in 2020, and forty-four in 2029.  In any of those scenarios, he could have become a problem for Skynet.  We might question how a twelve-year-old John Conner became a problem for the 1997 version of Skynet, but it's not impossible that with his training he would get there over time.

Sarah and Kyle leapt to 1997, but the 1997 launch and the 2004 launch were eliminated.  They might have had their first child as early as 1998, which means in 2017 he was nineteen, and could be the rebel leader; in 2029 he would have been thirty-one.

Suddenly Sarah and Kyle are connecting in 2017.  The 2017 launch has been eliminated, and we can extrapolate that whatever it was that Cyberdyne discovered that Skynet wanted to protect has also been destroyed, so the launch date is going to be later.  However, the earliest possible birth for Sarah Conner's child is now the summer of 2018 (assuming an October 2017 conception).  In 2029 he will be turning twelve.  He is not going to be the rebel leader Skynet fears.

Of course, the filmmakers will want us to think that Skynet still will come into existence, but at a later date, and that therefore the later birth of John Conner is not an issue because he can be the thorn in the flesh of the later incarnation of Skynet.  That was probably a significant part of the point of the storyline:  move all the events to a later date so that we can keep continuity and keep the same heroes but have new later dates for the events that are still comfortably in our future.

The problem is that in 2029 John Conner will not be a problem for Skynet, and so Skynet will not send a T-800 back to kill Sarah in 1984.  That again changes everything, because without that T-800 Sarah and Kyle cannot leap to 2017, and so will have their child again in 1985, and we have an infinity loop.  It is again a complicated one--because their absence from 2017 means that Genisys becomes Skynet thanks to T-John's intervention, and their presence in 2017 means that John is not born in 1984, they cannot travel to 2017, and T-John never came to 2014 to protect Skynet.  It's a disaster.

We might try to construct a complicated solution by having John born in 1984 but Sarah and Kyle destroying the T-1000 in 1996 and then using the chip from the other T-800 to go from there to 2017, but we are on the edge of oblivion here:  if John then becomes a problem for Skynet, the T-800 is sent to 1984 making it so that he does not (because Sarah uses that processor to leap to 2017), and we have an infinity loop; if somehow history stabilizes without the sending of the T-800 to 1984, the reason for sending Kyle to 1984 weakens drastically.  Of course, a child born in 1985 would be nine in 1996, and if they took him with them to 2017 he would be twenty-one by 2029, so this might preserve the timeline so that Kyle is sent back to father John even though there's no T-800 after Sarah.  However, when 2030 arrives there won't be a T-1000 sent to kill John Conner in 1997, because there will be no trace of him in 1997, and that means the T-800 won't be sent, either, which means there is no chip to use to move Sarah, Kyle, and John to 2017.  Further, by 2030, Skynet no longer wants to kill John Conner or his mother--Skynet owns John Conner, and needs John Conner to jumpstart its existence.  The story is over.

We have many times analyzed time travel movies that destroyed time somewhere in the middle of the story, and we have said fine, the story ends there, but what does the rest of it look like?  There's not much more to tell on this one.  We have the significant problems that it is unlikely anyone will send back the T-X or the 2004 T-800, and that Kate Brewster is out of the equation.  Marcus Wright is a wild card, because he probably was not activated in 2018 to target John Conner and Kyle Reese so we don't know when he might emerge.  Pops might still be sent to 1973 to protect Sarah, which might prompt Skynet to send the T-1000, and ultimately the T-5000 will be sent.  This time it knows that T-John's arrival in 2014 will cause Skynet's launch in 2017, so that will be included in the program.

Looking in the other direction, the destruction of Cyberdyne has this time undone the original launch date that we never discovered (because something Cyberdyne developed around 2014 preciptated it in some way, and that's now lost), but we have a new anticipated launch based on the preserved Skynet core in the ruins of the Cyberdyne building.  They will undoubtedly attempt another movie based on that.  Our analyses are going to be complicated, of course, because what they have done to this point has created an impossibility so we are building on a history that cannot have happened--but we've done that before.  Although this is starting to have a lot of the marks of why we do not analyze television series and other media, it was an enjoyable movie to watch, even though it was a very frustrating one to analyze.

In our original Terminator analysis we made some suggestions for the third film.  This time there is nothing that can be done, but it occurs to me that an excitng movie could be made if in this new history Skynet sends perhaps another T-X from any date after the sending of the 1973 T-1000 to around 2020 to target two-year-old John Reese.  However, this is entirely implausible.  Skynet now needs John, so it seems Terminator needs new heroes for the next generation.

Maybe the hero can be Kyle and Sarah's second child.

Footnote:  For more thoughts on a future for the Terminator series, see mark Joseph "young" web log post #28:  A Terminator Vision.