Jack the Ripper uses a time machine invented by futurist H. G. Wells to escape the police and vanish into the twentieth century; Wells pursues him, is shocked to discover that the future is not at all what he had always envisioned, and falls in love with a thoroughly modern woman.

If you have not yet seen Time After Time (a dashing young Malcolm McDowell and a critically-acclaimed performance by Mary Steenburgen at the height of her acting career (she would win a Best Supporting Actress Oscar the next year for Melvin and Howard)), do so.  The 1979 movie is on the must-see list for fixed time theory films.  (And a special time traveler films recognition to both:  Steenburgen, who a decade later would appear as Doc Brown's love interest in Back to the Future Part III; and McDowell who played Soran in the seventh movie in the science fiction series, Star Trek Generations.)

In brief (and with spoilers), Herbert George Wells has not started his literary career in 1893, although he worked as a newspaper writer for a while and made money promoting what he considered futuristic areligious socialist ideas such as women's equality and free love.  He aspires to be a private scientist and inventor, much like time traveler Alexander Hartdegen in the 2001 version of The Time Machine, modeled after men like Edison.  To this end he has designed and built a solar-powered machine that by the juxtaposition of opposing electromagnetic fields travels through time.  He has not yet dared to test it, but is showing it to a small gathering of mostly unnamed friends when the police arrive asking permission to search the house.  It seems--as we saw in the opening of the film--that Jack the Ripper has just murdered another prostitute not far from Wells' home, and they are searching the area for clues.  They find the medical bag of the last guest to arrive, local hospital chief of surgery Doctor John Leslie Stevenson, in which are a pair of blood-soaked gloves.  Stevenson, however, has vanished--as has the time machine.

However, Wells installed a safety feature:  he has a key in his pocket, and while anyone can operate the machine, without the key it will return to its point of departure a few minutes after it has reached its destination.  Thus a moment after Wells discovers the machine gone and realizes Stevenson took it, the device returns, badly overheated, and Wells is able to read from the display the date of the destination.

With only minimal preparations, he pursues Stevenson into the future, finds himself not in London but in an H. G. Wells exhibit on loan from Britain to a museum in San Francisco.  Most of the movie involves his pursuit of Stevenson and the latter's efforts to obtain the key so that he can escape this pursuit without fear of being followed.  In the process Amy Catherine Robbins, from the currency exchange desk of the Chartered Bank of London, is swept into events, having exchanged currency for each of the travelers, told Wells the hotel she recommended to Stevenson, and become romantically attracted to Wells.  When he finally tells her who he really is, he has to prove it by taking her three days into the future, to Saturday night, where the Saturday paper on the desk at the museum identifies her as the fifth victim, Friday at 7:30, in the mysterious new string of serial killings.  Wells insists they return to Wednesday to consider the problem, and in their discussions she rejects the idea of traveling to the past with him because she would not fit in that world, and then they agree that they cannot leave for the future without doing something to stop Stevenson first.

The situation becomes more complicated as Wells is arrested on suspicion of being the murderer, Amy is taken by Stevenson as a bargaining chip to get the key, her friend Carol is killed and dismembered at her apartment (and misidentified as her), but we ultimately have a good Hollywood ending.  Stevenson is vaporized by the time machine, Amy agrees to travel back to 1893 to marry Wells, and he writes his books about the future.

All of that works somewhat smoothly if we assume the immutability of fixed time.  At issue for us is what it takes to make it work under some other theory.

Of course, how a time machine works is only of passing interest to us; we address it only if it cannot logically work that way (such as sling-shotting around the sun one direction to go back in time and the opposite direction to come forward, as in Star Trek IV:  The Voyage Home).  However, there is another sense in which we do ask "how" the time machine works, that sense in which it dictates the limits of what it can do.  In the present film, we observe that the machine travels two years per minute, and is calibrated to the nearest whole day offset by the time it takes to make the trip.  Thus when Wells leaves 1893 at about ten thirty expecting to move forward to 1979, a temporal distance of eighty-six years, he anticipates the trip taking forty-three minutes and his arrival time to be eighty-six years and forty-three minutes after his departure, about quarter after eleven.  The trip from Wednesday to Saturday requires barely a blink of an eye.  (At roughly twelve days per second, three days would take about a quarter of a second.)

However, he arrives around two thirty, almost eight hours earlier than anticipated, and the reason for this is interesting:  it is almost eleven thirty in London, but the machine arrives in San Francisco.  It is again suggested that it arrived there because in 1977 it was unearthed in London, added to the Wells exhibit, and loaned to the San Francisco museum--in other words, because the future version of the machine was moved to a different location, that is where the past version arrived.

There would be a logic to this, if we then take it that the machine itself does not actually travel in time and so does not duplicate itself, but only transports those within it from wherever it is at the moment of departure to wherever it is at the moment of arrival.  That would mean that it cannot be used to travel to a moment before its own initial completion.  When one of his guests suggests making such a trip, Wells does not seem to think that impossible, just not what interests him.  However, he never says it could make such a trip, and even so it never does so, so possibly it cannot.

However, if it worked that way, it would not vanish from his basement either when Stevenson left or subsequently when he left; it would remain there, and the occupant would vanish into the future.  Yet it must work that way, because otherwise when Wells takes Amy forward four days they would arrive to an exhibit cordoned by police tape, as investigation into the mysterious disappearance of the pride of the exhibit would be ongoing.  Oh, but wait--they put it back, so perhaps it is not missing the next day.  Yet does it not disappear Friday night when Wells and Amy leave for the past, so as to be missing when the police arrive (the alarms are sounding), and so in that case have indications of a police investigation at the scene when they arrive on Saturday night?  And indeed, what becomes of the version of the machine that was unearthed in 1977, if the one currently in the museum is the one that traveled there from 1893?  Or does the machine somehow overlay itself, as the T.A.R.D.I.S. in the end of The Five Doctors, splitting into the one that came from and is returning to the past and the one that belongs in the future?

The notion that the time traveler travels to wherever in space the time machine happens to be at the moment he arrives is brilliant; it has some problems (addressed in connection with the 2001 version of The Time Machine, but it also resolves such issues as frame of reference (why is the time traveler not left behind when the earth moves away from his starting point).  It is an elegant idea in some ways.  However, it is not followed consistently here, and exactly what is happening is never clearly explained--indeed, somehow Wells himself never seems to wonder why he landed where the future version of the time machine was instead of in London as he expected.

It is one of those questions that has a silly answer:  the author wanted Wells and Stevenson chasing each other in San Francisco, where they would clearly be foreigners and not know the terrain or the culture (in addition to not knowing the history or the technology), and this was a way of getting them there that might cross our credibility gap if we did not consider it too deeply.  The explanations do not make sense, and the film wisely does not belabor them.

The first trip through time works on any theory:  Jack the Ripper uses a time machine to escape into the future, never to return, and so he is never caught in the past.  The second trip, though, is easy to overlook, because no one makes it; the empty time machine itself returns from 1979 to 1893 because Stevenson did not have the key that Wells kept in his pocket, which allowed it to change its home time.  It is this trip which gives us our first puzzle in relation to the nature of time in the story.

The problem is that Stevenson has created an original history.  In that history, he vanished with the time machine in 1893; eighty-six years of history containing two world wars and a few smaller ones along with women's liberation and the civil rights movement (and several assassinations) and the moon landing unfolded before he could appear in 1979.  During those eighty-six years, the time machine never returned to the basement of Herbert George Wells.  He may have waited hours, even days, for it to do so; he may have wondered where it went, or even whether it worked.  He did not, by any stretch of the imagination, leap into the machine a few hours later and pursue Stevenson into the future.

At this point, there are three possibilities concerning the two relevant facts in that original history.  Either Wells built another time machine or he did not; if he built it, either he used it or he did not.  He may have concluded from the failure of the machine to return that it does not work, and that Stevenson disintegrated along with the machine, and so abandoned the project.  He may have built one, but the uncertainties surrounding the disappearance of the first increased his doubts and prevented him from testing it.  There are, however, two reasons to suppose that if he did build and use another machine, he will have traveled to the future.  First, his interest was always to see the future, the supposed socialist utopia he anticipated.  If he decides there is no chance of finding Stevenson, this is where he will go.  Second, if Jack the Ripper escaped to the past, Wells would expect to find some trace of him in history.  The absence of any such trace does not prove Stevenson did not go that direction, but it means that there is no trail to follow, and the future is the better bet.

If he travels to the future, he has a window of eighty-six years.  Once he reaches November 5, 1979, the time machine taken by Stevenson will depart for the past, and by its arrival in 1893 will change history.  The most significant change it makes is that Wells will never build the other time machine, and thus unless he has created an infinity loop or sawtooth snap within the time prior to 1979 (preventing time from reaching 1979 in this iteration of history) everything he does in this original history is erased as the new history is formed.  We saw something similar in The Philadelphia Experiment, as he undoes his departure and creates a new history in which the return of the time machine is always part of events.

That new history becomes the next problem, because his possible trips through time are not the only thing he undoes.

Normally when someone travels to the future, no anomaly is created.  However, the third trip made in this film should cause us to puzzle.  That is, Stevenson steals the machine to make the first trip to 1979, creating the the original history, and then the second trip is made when the machine returns to 1893.  During that original history, Wells may have traveled through time or not, may or may not have written books of some sort, and may or may not have become famous.  If we give him, and the story, the benefit of the doubt, we conclude that he wrote some excellent futuristic books and that there was a museum exhibit dedicated to him.  We might even suppose that he built another time machine, which was unearthed in London in 1977 and became part of the exhibit.

All of that is erased when the time machine returns from 1979 to 1893, as Wells leaps into the time machine and rushes forward to 1893, removing himself from history.  He now has never lived through the dawn of the new millennium and the first half of the twentieth century--not merely, as the film amply demonstrates, that he has not yet done so, but that those years passed without his presence.  He is now an unimportant newspaper writer who vanished in 1893 immediately after Jack the Ripper killed his last victim, not long after Doctor John Leslie Stevenson also vanished purportedly from his house; he might possibly appear in books trying to solve the Ripper murders, since it might be guessed that Stevenson managed to hide then came back and murdered him, or that he murdered Stevenson, attempted to frame the doctor, and then fled when he thought suspicion would soon fall on himself.  Further, he takes the time machine with him, and locks it in 1979, so there is no time machine in London to be unearthed and included in any exhibit.  We can quibble that there will be no picture of him at sixty-seven years old, but more seriously there will be no Wells exhibit, and neither the police nor Amy will ever have heard of Herbert George Wells.

This changes everything.  It means that the time machine was never moved to San Francisco, and thus that both Stevenson and Wells emerge somewhere underground in London.  There is probably no egress; it is questionable whether Stevenson can even exit the machine, or survive its arrival (the time traveler in The Time Machine was concerned that he might materialize inside solid rock and so be killed).  If he arrives in an underground pocket that had once been Wells' cellar, he will be stranded there for just shy of two hours (forty-three minutes while the machine travels back to 1893, roughly fifteen minutes while Wells organizes for his trip, and forty-three minutes while Wells travels to the future), and the arrival of the machine will be his salvation.

There might be a fight.  At this point there is no certainty what will happen.  Perhaps Stevenson is weakened from lack of oxygen, and Wells easily overcomes him; perhaps Wells is beaten but manages to pull the vaporizer stabilizer from the machine before Stevenson can strand him there.  Two things are certain, though.  The first is that in order for the story we are told to happen, Wells must return to 1893 in the time machine and restore his place in history by writing those books, so that he will create the new history in which he is a famous author and the exhibit honoring him travels to San Francisco.  The other, though, is a bit more complicated, and impacts what must have happened in this history.

Before we get to the second certainty mentioned regarding those erased trips to London, there is a peculiarity in Wells' actions at the moment the time machine returns.  He rushes around the house, asking Mrs. Turner (the housekeeper) for all the household money and her own jewelry, and making very hasty preparations for a pursuit mission to the future to capture Stevenson before he can besmirch the supposed utopian society of 1979.  It is evident that he wishes he could prepare better--he might take a gun to the presumed peaceful future, he might take more than fifteen pounds in currency, or obtain some gold or other significant resources.  He knows he could be better prepared; but he fears that he will lose the trail if he lets too much time pass.

Why?

In all seriousness, November 5, 1979 is eighty-six years in the future, and he has a time machine.  Granted, as we noted, it travels to the same time on the target date, and so the longer he waits tonight, the more time will have elapsed in the future; however, there is no reason why he cannot get a good night's rest, stop at the bank first thing in the morning, pack a bag of useful items, leave right after tea, and by setting the machine for November 5th arrive several hours before Stevenson, being there to ambush him upon his arrival.  In a chase through time, all the rules about "before" and "after" are subject to adjustment.

We will forgive H. G.; after all, it is his first experience with time travel, and since he has not yet written that first book on the subject, neither he nor anyone else is yet thinking four-dimensionally.  He is upset and not thinking clearly, and he makes a foolish error.  He could have done that much better in a dozen different ways, had he only allowed himself a bit of time to consider it--and as he eventually notices but never fully grasps, time is on his side.

We previously noted that since Wells removes himself from history by leaping into the time machine and traveling to the future, he prevents himself from becoming the famous author whose life is chronicled in the museum exhibit, and therefore that the time machine was not moved to San Fransisco, and both Stevenson and Wells arrive somewhere in London.  It is indeed more complicated than that:  since the time machine had not returned to 1893 the second time (when Wells takes it, he has the key) it will not have been excavated.  We do not know the conditions in which the machine appears in the future, but we face another problem if we are to get the story we see in the movie.  Wells must not return with the time machine before late in the evening of Saturday, November 10th.  Otherwise, we hit an anomaly that destroys time.

We know that Wells will reach London on November 5th, 1979, at about 10:30 at night, and that Stevenson gets there first.  We considered the possibilities that the time machine would then be buried, and that Stevenson would have nowhere to flee.  In that case, Wells arrives at 10:30, retrieves Stevenson, and returns to 1893 a few minutes later, creating a new history that begins at the moment of his return to 1893 (roughly quarter after eleven on November 5th) through the moment of his departure from 1979 (roughly half past ten on the same date of that year).  However, the entire history is dependent on Wells returning from that future with (or possibly without, if Stevenson died in that hundred-some minutes) Stevenson.  If Wells does not arrive in 1893, that history is undone; and if he does not depart from November 5th, 1979, by roughly 10:30, he does not arrive at the necessary time in the past.  He can only be in the future beyond that moment if he has already stabilized history through that moment, and in this next version of 1979 he arrives in San Francisco, not London, and does not find Stevenson awaiting his arrival, and therefore does not return to the past immediately.  Yet the minute his departure time is passed, he undoes the history leading to the moment of his new arrival time, and time ends.  We know that when he arrives in San Fransisco he stays until Friday night, and additionally that he makes a forward trip to Saturday night--days that cannot exist until he makes his return trip to 1893.

The only solution to this problem is that Stevenson was not with the time machine when Wells arrived in London at ten thirty on that November 5th evening; somehow he left, and Wells, with his handful of ancient currency, had to find him.  Yet there is some hope that this might be so.  We know that the time machine, in the final version, was unearthed in 1977 in excavations in London, and there is not much archaeological research in that city, so it is likely that the excavations were part of efforts to build a new structure, perhaps the foundation of a taller building or part of a subway.  The time machine may have arrived in such an open area, and when it returned to 1893 abandoning Stevenson in the future, he abandoned the landing site to make his way into the new world of the future London.

Upon his subsequent arrival, Wells began his search for Stevenson.  This took several days--he left for the past not sooner than late Saturday night (because we need that much time for the next history, to prevent an infinity loop).  However, there is good reason to suppose it would.  Neither of our travelers will have to exchange foreign currency, neither will appear foreign (although their period clothing might catch some attention).  Wells will be an unknown, and will have no reason to hide his identity under a fictitious name.  It is not at all unreasonable to imagine that he is still searching as late as November 10th, and that on that date or sometime thereafter he either succeeds or abandons the chase, returning to his own time to recreate the history in which he is a famous author.

Only in an adventure something like this do we get the necessary starting point for the adventure we see, in which Wells is a soon-to-be-famous author pursuing Jack the Ripper into the future.

In an effort to prove his story to Amy, Wells takes her forward to Saturday night, November 10th.  At first she is unimpressed; after all, the interior of the closed museum is much the same on Saturday night as it was on Wednesday night.  However, she then finds Saturday's newspaper left conveniently on the counter in the entry, and is shocked to discover that she is reported slain on Friday night.  He then says one of the strangest things he says in the movie:  he tells her that they have to go back.

If we have embraced a fixed time explanation of the film, and we accept that she was indeed murdered on Friday night, it is obvious to us that one way or another she must return to a time prior to the murder so she can be killed.  The problem is not whether or not they must return to Wednesday night, but why it is that they think they must.  Neither of them is thinking, "We must return because Amy is destined to be murdered on Friday so we must be there in time for that to happen."  Once they have returned, they discuss the possibilities of escaping this fate by leaving for the past or the future.  There can be no motivation for them to believe that they must return to Wednesday.  The only possible reason for them to think they must do so is that they are compelled to think this so that they will do it, preserving fixed time.  It is the Achilles' Heel of fixed time theory:  if it is true, we have no free will.  In this case, though, it seems they lack even the illusion of free will:  they are compelled to return without any clear reason to do so.

Of course, it is not Amy who is killed.  It is Amy's friend Carol from work, whom earlier Amy invited to dinner on Friday.  That does not change the situation much, though, because had Amy stayed in the future she would have been missing from work Thursday and Friday, without a phone call, and Carol being unable to reach her would probably not have come for dinner, and so would not have been murdered.  That would have changed the headline in the paper, because neither Amy nor Carol would have died and no body would have been found in Amy's apartment; that in turn would have removed any reason they might have had not to return, and put the headline back in the paper, and we would have had an infinity loop.  That, though, gives us another problem.  When Wells takes Amy to Saturday, they are missing from the world for those intervening days, Carol does not come to Amy's apartment and so is not murdered, and the newspaper will not report Amy's death and has no reason to report her disappearance.  There is thus again an original history in which they are absent.  It is only when they return and live through those days that we get the report of her murder, which they then find when they travel from Wednesday to Saturday.  This, though, means that unless Stevenson kills someone else on Friday night the murders will not be the Saturday headline, and they will have no information about the murder of Delores Marx at McLaren Park.

Since they are going to find the Saturday paper only, in order for the story to move forward they must, in that original history, find a paper which reports the deaths of Delores Marx and someone else; Stevenson is compelled to kill, and so we have the probability of a murder that will make the headline.  Wells and Amy return to Wednesday armed with the paper and the intention to prevent the deaths of the two people mentioned in it; but their presence in this timeline alters Stevenson's plans, with the result that when Carol comes to have dinner she is killed, Amy taken as a bargaining chip.  There is, however, a problem in this, because of that newspaper.

If Amy jumps from Wednesday to Saturday, she cannot be killed on Friday, and it is highly improbable that her friend Carol would come to see her and be killed on Friday at her apartment.  Yet for Amy to believe Wells' fantastic tale, she must find the paper on the table in the museum; and for that paper to be of use to them in their efforts to capture Stevenson, there must be a current story recounting the deaths that had occurred.  It is likely that such a story would be on the front page of Saturday's paper only if Stevenson killed someone late Friday or very early Saturday.

If he does not, Wells and Amy have no clues to lead them to Stevenson, and we are stymied as to how they will find him--but that he has left a note demanding the key and threatening Amy's life.  Delores Marx will be killed on Thursday, and then on Friday Stevenson will face Wells and fight over Amy, probably killing (or at least threatening) Carol.  The police will not be questioning Wells, because he did not report the murder of Delores and so is not suspected.  One way or another Wells defeats Stevenson.  Presumably Carol is killed, someone reports the murder, and it is reported as Amy, putting it in the paper for the version we see.

If (in the original history) Stevenson kills someone else on Friday, we have a front page headline story reporting it, along with the names of the previous victims including Delores killed in McLaren Park; but there is a different Friday victim.  Wells calls in the Marx murder, is brought in and held for questioning, and shows the police the paper in which there is a murder predicted, but not Amy's.  The police do not believe him anyway, and continue to hold him until such time as Amy's murder is reported, at which point they release him.  Stevenson never intends to kill Amy; he intends to use her as a bargaining chip.  Amy already invited Carol, so it is Carol who is killed.  The police might threaten Wells with interference with a police investigation, since the incorrect identification of the victim (which they did not pursue anyway, as they thought Wells was the murderer) confirms their belief that it is a novelty newspaper.  Wells wonders why the paper was wrong, but again he manages to defeat Stevenson and save Amy, then leaves for the past.  She probably goes with him.

Of course, if they prevent the murder of Delores Marx, it will not be reported in the paper; probably nothing will be in the paper, if Stevenson is caught on Thursday, and that means they will not have the information needed to prevent the murder, and we have an infinity loop  However, the only difference in the timeline in which someone, not Amy, is identified as the Friday victim is that there is less stress on the twosome to solve this quickly.  It is possible that the absence of Amy and Wells might (butterfly effect) cause Stevenson to kill someone else on Thursday night, but it does not appear as if they had any significant impact on him Thursday so this is unlikely.

Ultimately, then, we have the history in which having visited the future and returned, Wells and Amy cause the existence of the headline reporting her murder, which turns out to be Carol.  That becomes the paper they find when they travel from Wednesday night to Saturday night, and the paper tells them of Amy's murder, which gives us our final version of the history we see.  At the end, on Friday, he takes Amy back to 1893.

The movie is finished, but we are not.  That return trip creates an entirely new set of problems, a new history to be examined.

There is an anachronism in the film.  When Amy tells of her divorce, Wells says that he, too, is divorced, and that it was because his wife wanted him to be conventional.  Had there been such a divorce, it would have had to have occurred (obviously) prior to 1893, and thus have been under the rules of the Matrimonial Causes Act 1857.  Divorce had to be for cause, usually adultery (although for women applying for divorce adultery had to be supplemented by another cause such as domestic violence).  It might be, however, that the previous Mrs. Wells was infidelitous, Wells divorced her, and rather than speak ill of her he simply excused her errant ways by blaming his own lack of conformity.  In any case, it is a small point; we take it that Wells is legally single and able to marry Amy Catherine Robbins when they return to 1893.  When asked about her family, she will simply claim that her parents are not alive.

What is more problematic for us, though, is the genetic issue.

It must first be remembered that this is not the first time through these years for Wells.  There is an original history, in which Stevenson fled to the future and never returned.  This is replaced by that history in which Wells removes himself from time to travel forward to London, and then by the history in which he returns to 1893 having defeated Stevenson in 1979 London.  That means there was an original history of the world in which H. G. Wells was part of history, his time machine having been stolen by Stevenson, and another history of the world in which H. G. Wells had visited 1979 London and then returned to live his life from 1893 forward.  Now we have a new history in which he brings a bride back from 1979 San Francisco.  What does this change, as compared with the histories in which he did not bring her back with him?

We might suppose that Wells never married in those other histories, and thus that there were no descendants whose lives have been erased by his failure to marry whomever he now does not marry.  However, to what degree would the best-selling author have been England's "most eligible bachelor", and how much impact would that have had on history?  It only takes one girl rejecting a suitor she would have wed in the hope of catching the fancy of another, or one man choosing not to propose because he (wrongly) believes the object of his desire will reject him in that same hope, and all the marriages of a generation are shuffled just enough to change who is born in the next one.

We can at least rest fairly safely in the conclusion that Wells is not Amy's ancestor.  His descendants will be in England, and if they emmigrate to America it will most likely be to the east coast; Amy is west coast, and probabilities are that she was born there.  Between 1893 and Amy's birth (probably the mid 1950s) the genetic impact probably will not reach her.

We cannot say quite so much for many of the leading British figures of the mid to late twentieth century.  Any of them, from C. S. Lewis to Margaret Thatcher, might not have been born.

These, though, are the stuff of possibilities, even probabilities, not of actualities.  It is not impossible that the world could unfold much as it does, and stabilize into the form we know.  It just has to be remembered that with time travel there are hazards we tend to overlook, and taking Amy to the past with him was the most dangerous thing Wells did.

There is another point that should be noted.

We now reach perhaps the most vexing question of all:  to what degree did Wells' trip to the future, and perhaps even more so Amy's trip to the past, influence his writing?

We have an author famed for writing several books about space, including famously the first one to put people on the moon and the first one to bring alien invaders to earth, plus the book about traveling to the distant future.  He lived at the dawn of a technological age, in which there were already a few automobiles and electric lights and telegraphs; he wrote of so much more.  The film suggests that he saw and heard what really are barely more than glimpses of our world--a brief passing view of the Apollo missions (misplaced as the last one had been completed in 1972), reference to two world wars and at least one other, and the technology that from his perspective must overwhelm the world.  The question is, did this impact his writing?

The question also goes deeper.  The 1893 version of Wells in the film is an optimistic progressivist; his fear when Stevenson takes the time machine is that he has unleashed a terrible evil into a future socialist utopia.  The Wells we know from his writings, though, is generally deemed to have been a pessimist--perhaps not so pessimistic as Orwell (the socialist whose famous books depicted socialism as an unworkable system which broke down into oppressive oligarchies).  Should we think that having seen the horrors of the future Wells changed his perspective?

It is a difficult question to answer.  However, the film avoids putting Wells in contact with too much of modern technology, and particularly with aspects about which he was to write.  We don't have Wells giving us prescient details of the technological future; he did not take the time to learn that much.  It may be, too, that Amy decided early not to give him too much information about what was going to happen, for reasons of her own.  We can imagine that his brief exposure to the technology of the future would not influence the imagined technology of his writings sufficiently to alter his success as a famous futurist.

Yet it is that pessimism that is the challenge.  The Time Machine works because it extrapolates the lords of England into the futuristic cattle-like Eloi and the lower classes into the carnivorous Morlocks.  His pessimism about the future may be one of the aspects that gives his books interest and tension--do we want to read about his envisioned future utopia?  Had he not developed that pessimism regarding the future, his books would have been very different; even today, futurists who hold an optimistic view of the future (e.g., Vernor Vinge) tend to write science fiction stories portraying rather negative aspects of it.  Conflict makes for a more compelling story.  Unsullied utopias make for dull reading, most of the time.

Yet perhaps this is the saving grace:  the optimistic Wells could easily have divined that pessimistic stories made better reading and so sold better, and written his books with that in view.  His trip to the future then broke his optimism, and the feigned pessimism of his tales became real.

There is an odd temporal twist created by the interaction of three of our trips through time.

It begins innocently enough, as on Wednesday night Wells decides to take Amy forward to Saturday night, so they hop into the time machine and leap forward.  Of course, Saturday has to come into existence, but there is no problem with that occurring at this point; it simply means that in the original history Wells and Amy vanish on Wednesday night and are not seen again until--well, Saturday, except that they aren't seen then, either.  In this history Stevenson killed Delores Marx and some other girl, and probably since they were not there to stop him Friday is killing yet another while Wells and Amy are at the museum.  Then they return to Wednesday, beginning the new version of those few days.

On Friday night, having vaporized Stevenson, Wells and Amy make their trip to 1893.  That means that they begin a new history which runs from 1893 to that Friday night in 1979; it also would seem to mean that that Saturday on which they found their newspaper never happened--this timeline came to an end when they left for the past, and Saturday cannot begin until eighty-six years and a few odd days have passed and been successfully confirmed as the new version of history.  Or does it?

The complication arises because Wells and Amy have already traveled to Saturday, and returned to Wednesday.  Now when they depart from Friday they appear to create an anomaly that ends on Friday, undoing Saturday until this anomaly is resolved, and thus making it impossible for them to have reached Saturday from Wednesday.  However, we know that they visited Saturday before they created this anomaly, leaping past Friday in their original history, and then returning to Wednesday.  Thus what we really have is an anomaly in which two travelers left from Saturday and returned to 1893, with a stop on Wednesday that was extended through Friday.  Had they stopped on Wednesday simply to pick up a dropped paper and then continued to 1893, we might not even have noticed; it is not entirely different given the longer stay, as long as they did nothing that would prevent them from arriving on Saturday.

Of course, we have the problem that the museum is going to think the machine was stolen, first on Wednesday and then not on Wednesday but on Friday, and that means that the experience they had on Saturday will be slightly altered, but it should not be a fatal change.

It is a bit odd, but not impossible.

When Wells is finally headed back to 1893, he makes a comment which could be fatal to the entire story, regardless of which theory of time you choose.  He says that because man is not at all ready to have access to time travel, he intends upon returning to the past to disassemble the time machine.

Let us assume that he does.  He seems rather intent on doing so.  In that case, there is no time machine to be unearthed in 1977, and whether or not there is a traveling H. G. Wells exhibit, the machine is not part of it.  That is severely critical, because the very weak reason given for Stevenson and Wells to wind up in San Francisco is that that is where the 1979 version of the time machine happens to be.  Remove that, and they arrive in London, with all the complications involved there.  Further, we have to assume that in the history following Wells' return from London he does not disassemble the time machine (or it would not exist to be discovered and moved) and therefore if he does so after his return from San Francisco, we have an infinity loop alternating between the post-London history and the post-San Francisco history.  Time is undone.

Nor do we resolve this by deciding that Wells has somehow sabotaged or deactivated the time machine.  The logic of landing in San Francisco only works (to the degree that it does) based on the assumption that the museum has a functional time machine no one has ever bothered to test.

Note that the destruction of the time machine would be as fatal to a fixed time explanation of the story as to any other:  if the machine existed to be uncovered in 1977, then it is impossible that Wells destroyed it whatever his intentions were in 1893.

The simple and obvious solution is that despite his promise, Wells did not disassemble the time machine.  Perhaps he thought he could keep it hidden (only Amy and Mrs. Turner know that it actually works) and that it would be a shame to undo this great success in his life until he had some other success.  Perhaps it is as simple as that Amy insisted he keep it--it is, after all, her only possible ride home, should she ever wish to visit her family, or if this her second marriage also fails.  We sometimes talk about being trapped in a relationship, but without that machine she is well and surely trapped.  So it is reasonable to conclude that the Wells family had their own private time machine which perhaps they never again used (or perhaps they did, once or twice, to visit her family), which they kept in a secure section of the basement, where it would be unearthed decades later.

As we have seen, then, the film is possible, but it is a very difficult story to derive by replacement theory.  It does work under fixed time, but leads into that serious issue concerning their return from Saturday to Wednesday, and the suggestion that they make the irrational choice because they have no free will to do otherwise.