There are cases in many stories (usually science-fiction or science-fantasy stories) in which an infinite time loop is used. What is fascinating about this idea is the way a seemingly impossible premise is presented: the fact that certain events in time repeat endlessly, or that certain points in time serve as starting points for infinite events.
To explore the basics of the infinite time loop, what will be discussed are the two most common infinite time loop examples: The fixed infinite time loop and the unfixed infinite time loop.
A fixed infinite time loop is like a circle; it has no definite beginning or end, but repeats itself eternally. To explain a fixed infinite time loop, two different stories will be used as examples.
Example number one is the story told in the Terminator film trilogy. The first Terminator’s entire story pretty much revolves around an infinite time loop: Events cause other events that, in turn, end up causing the original events. It went like this:
- Sarah Connor gives birth to John Connor.
- John Connor grows up, leads humanity’s fight against the machines and wins.
- Realizing Skynet has sent a Terminator back in time to kill his mother and make his birth impossible, John Connor sends Kyle Reese back through time to protect Sarah and thus himself.
- Kyle meets Sarah and rescues her from the Terminator.
- During their time together, Kyle and Sarah fall in love and end up having sex.
- Though Kyle is killed by the Terminator, Sarah survives and finishes the Terminator off herself, leaving only its arm intact.
- The discovery of the Terminator’s arm leads to the eventual creation of Skynet, which tries to destroy humanity with its army of machines.
- Because she had sex with Kyle, Sarah becomes pregnant. (List repeats ad infinitum.)
The cycle repeats endlessly. Nothing about it ever actually changes; the events of the time loop are identical every time it occurs.
Example number two is the Doctor Who novel Festival of Death by Jonathan Morris. In this book the Fourth Doctor and his companions Romana and K9 arrive on a space station that is trapped in hyperspace. The Doctor and Romana are warmly greeted and thanked for saving the station, something neither of them has any memory of doing. Also puzzling is the way K9 is regarded with great fear despite never having done anything to anyone. After a while the Doctor comes to realize that he and Romana were in fact responsible for saving the station, it’s just that they haven’t gone back in time to do it yet. One troubling thing, however, is the fact that the Doctor discovers that he was killed in saving the station… and thus he means to search for a way to save the station without dying.
It is the Doctor’s knowledge of what he has already done and what has already occurred that leads him to make many of the decisions he makes when he travels back to an earlier point in the station’s history to save the people on board from destruction. By landing the TARDIS on the station during the aftermath of the excitement, the Doctor places himself, along with his companions, inside a time loop that repeats itself as follows:
- The Doctor, Romana and K9 use the TARDIS to travel back in time, landing on the station while it is functioning normally and everyone is alive and well. They immediately set out to try and save the station from the disaster they know is coming.
- The disaster in question strikes and many people aboard the station are killed. Worse still, creatures called Arachnopods are unleashed and begin eating any living thing unfortunate enough to cross their paths.
- The Doctor manages to save the station but is killed in doing so.
- The Doctor, Romana and K9 first arrive on the station, finding it in disarray.
- The three travelers discover many people wounded or killed and a considerable amount of things destroyed.
- The Doctor and his friends are thanked for saving the station and those who are still alive, although they have no recollection of doing this. The Doctor decides to investigate.
- The Doctor learns he died while saving the station and decides to travel backwards in time to save the station and keep from being killed in the process.
A chapter of the book reveals that the Doctor goes through this loop an unspecified number of times before finally finding the solution he was searching for: saving the station and its survivors without meeting his end. It is because of this we learn that what was happening was an infinite time loop and not just a case of seeing the future to help correct the past. When the Doctor manages to save the station and himself, he leaves some instructions with the K9 his earlier self travels with, thus insuring that the time line will continue to flow as he remembered it. Thus the Doctor, Romana and K9 eventually escape and return to their space-time travels, but the infinite time loop continues.
An unfixed infinite time loop is a little trickier to explain, so I will begin by using the following example:
Imagine a column. This column stretches downward into infinity, with no visible top or bottom. Imagine this column represents a single point in time. The column, in its entirety, is one single point in time.
Now imagine a staircase leading out of this column and downwards. A descending staircase that leads away from the column. Imagine this staircase is the time line. The staircase represents the flow of time and the events that occur within the time line.
Now imagine that as we leave the column and descend the staircase, we are moving forward in time. Now let’s suppose that events occur that are not meant to occur. These events disrupt the time line, causing it to deviate from its original course. The staircase represents this deviation by curving. The events lead to other events that were not supposed to occur, causing the staircase to curve more. Eventually these events lead to a major bad event, and the staircase has curved around to the point that it leads right back into the column again.
By returning to the column, we have returned to the earlier point in time. Never mind the fact we’ve descended, because as I stated above, the column in its entirety represents a single point in time. Once we return to the column, we, in effect, return to that single point in time. So let’s say we decide to leave the column again, so we depart from the level we’re currently on and descend the staircase again.
Now, since we’re departing the column at a lower level than we did before, the time line is different. We’ve started off from the same point in time as before, but this time different events occur. Now let’s say that something completely different happens that wasn’t supposed to happen and again the staircase begins to curve until at last we return to the column once more. By returning to the column again, we again return to that one single point in time. And when we leave again, we leave at an even lower level, meaning that the time line has changed again and events are different from what they were above. This is an unfixed infinite time loop in a nutshell. Each time it starts off from the same point in time, but the events are not fixed; they change every time the loop begins again. And, in fact, the unfixed infinite time loop doesn’t cause itself the way a fixed infinite time loop does; outside forces usually cause such a time loop.
To give an example, there was an episode of Star Trek: The Next Generation called “Cause and Effect” in which the Enterprise D crew kept encountering a phenomenon in space, out of which a drifting ship appeared. The ship kept colliding with the Enterprise, resulting in the Enterprise’s destruction and the death of its crew, but then every time we came back from the commercial break, the crew was alive again, the Enterprise was intact and we joined Data, Worf, Riker and Troi during a game of cards. However, they began to realize something was up because they could hear voices, they had strong feelings of deja vu and they were able to remember things that, from their points of view, hadn’t happened yet. This story is an excellent example of an unfixed infinite time loop, which always begins at the same point and ends at the same point, but things in between are different each time until at last the crew (or, more specifically, Data) figures out what the deal is and they break free of the time loop and survive to explore another day. (The only problem with the episode was that we never learned what specifically caused the time loop in the first place, but oh well.)
To give another example, the anime series Higurashi No Naku Koro Ni tells a story in which, every two or three episodes, at least one of its major characters is brutally murdered. However, every time a new chapter begins, the story has started over and the dead characters are alive and well again. They have no memories of the prior episodes and they do not experience the same experiences when the story starts over.
I’d previously attempted to define the show’s format by drawing comparison to the movie Clue, which features different versions of its own ending (and thus different solutions to the mystery) which is in keeping with the game upon which it is based. However, that makes Higusashi’s story a series of what-if scenarios, and what I have realized is that this is actually incorrect!
Higurashi No Naku Koro Ni’s story actually is an unfixed infinite time loop. The story starts in June 1983 every time, but every time it starts over, something very different occurs. In one of the loops, Keiichi is the villain. In another loop, Rena is the villain. In yet another, Mion’s sister Shion is the villain. Different events occur each time, resulting in at least one character meeting a grisly fate. As soon as the loop ends a new one begins and suddenly everyone is back again.
What made me realize the story is an unfixed infinite time loop is when in episode four, Keiichi is given a drug injection by Mion and Rena which unhinges him, leading him to bludgeon the two girls to death with Satoshi’s baseball bat. He tries to tell Police Officer Ooishi what happened, but because of the drug, Keiichi claws his own throat out and dies before help reaches him. That episode ends its specific chapter and thus its specific loop.
In episode twenty-five, during a completely different chapter (and thus a completely different loop) Keiichi, upset by a conversation he’d had with Rena, makes a confession to his friends about something bad he’d done as a child (specifically, using a toy gun to hurt other kids) and his friends try to convince him that he doesn’t have to tell them all his sins; it’s okay to keep certain things secret. Keiichi then suddenly experiences something unnatural: he has a vision of what happened in episode four – he sees himself killing Rena and Mion with Satoshi’s bat. This greatly saddens him and he embraces Mion (who is unaware of having ever been killed by Keiichi and is thus a bit embarrassed at the sudden display of affection), stating he’ll never doubt his friends again.
This was the first clue I had. I got a second clue in episode 26 when Rika, thinking to herself, acknowledges that June 1983 keeps restarting and that she’ll play the little game she faces until the end. This is what told me that the series is actually an unfixed infinite time loop.
In a well-constructed story, an infinite time loop can be a fascinating way to explore events and even characters in different ways. During the writing of such a story, great care must be taken (especially when using a fixed infinite time loop) to avoid presenting a contradiction that cannot be sufficiently explained or revealed to be an important event that actually makes sense. It can be great fun imagining what we might go through if we were trapped in such a time loop ourselves… or if they might be occurring elsewhere.
 The second Terminator film actually made a mess of the story, because it attempted to knock out the infinite time loop by having the characters prevent Judgment Day and make the future different. This created a number of paradoxes, because John wouldn’t go on to lead humanity’s fight against the machines, which would mean no Terminator going back in time, no Kyle going back in time, no John being born at all, no Sarah even having any knowledge of the future and thus having no reason or motivation to attack the Cyberdyne building… now, while that could be addressed by the theory of parallel time lines, it still leaves too many things unexplained and seems, by the very definition of paradox, impossible. The third Terminator film put the infinite time loop back in place by revealing Cyberdyne’s destruction only DELAYED Judgment Day rather than prevent it, so John would still go on to lead humanity’s fight against the machines and win and so on and so forth. And since those events are part of the infinite time loop, they too remain the same as the cycle repeats.↵