Primer is by far the most sophisticated time travel movie I've ever seen. Did you know that director Shane Carrurh wanted the objects to stay inside the box when traveling back in time, so they keep their relative position in space? (remember that earth is moving so they need to challenge space as well as time, in order not to appear somewhere in outer space). In other words, they stay inside the box the whole "times", no matter "when" they pop out of it. The box keeps it's location on earth, and so are they. He mentioned Back To The Future where the DeLorean couldn't have possibly knew the location of which it needs to pop out at (?! sorry for my bad English, I hope this BTTF plot hole is understood). Carruth made a lot of efforts to untie any possible paradox.

As many others, I've watched the movie quite a few times and read a lot of information about it. The following suggestion refers to the most common analysis of Primer's timeline, and can be seen here.

It is assumed that Aaron and Abe visit the party many times before making the successful move (where the gunman is arrested and Rachel is safe). But when you think about the mechanics, there seems to be a paradox:

In order to go back after a failed attempt (or just an observation) they must have a box running. But when they go back in time, in the new timeline their doubles are also going to the party to have their attempt. Suppose the originals convince the doubles not to go, and let the originals go instead, since they have more experience. If they fail again this time, why would the doubles agree to stay in this timeline, where the party goes wrong? This implies both the originals and the doubles must go back together, which makes sum of series of doubles. Even if they stay in the hotel when the party is going, letting the ones that come out of the box to go there, there are still 2 sets of each person stuck there if they fail.

I can't think of any conventional way they could have loop over the party more then only one time. In this theory, they got it right the second time, and sent back the doubles with explicit orders of what to do. The originals would then stay in this timeline, and these are the ones we see arguing at the airport. It is possible that the doubles would fail and get stuck with the new doubles as explained above. In this scenario they will not get to the same airport scene.

If I squeeze the juice out of this theory, and add that 1) Aaron mentioned the term "sum of series" at the beginning of the film, and 2) considering the mindf**k scene at the end where he builds a huge machine, this could support the theory that they failed multiple times and are trying to fix it. Although this is a very flimsy theory.

Could anyone come up with a way they could loop back more than once?

I am again sorry for unclear language, please feel free to ask for clarifications.

  • The whole movie is a plot hole. Primer works because it creates good atmosphere by refusing to spoon feed plot points and using realistic props, not because it's accurate or coherent like all its fans try to make it to be. Jan 21, 2017 at 2:54
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    OP linked a very tiny version of the timeline chart, here's the original size
    – Lars Beck
    Aug 2, 2017 at 11:37

2 Answers 2


The narrator himself (Aaron2) is an Aaron who encountered a future Aaron (Aaron3) who looped back to do the party a second time. Aaron2 himself has been convinced by Aaron3 to not do the party, instead letting Aaron3 attempt to perfect it:

"So I left. He had already performed the task as I intended to, by recording the conversations of the day just in case."

Any set of Abe and Aaron who encounter future versions of themselves who looped back to redo the party would possibly leave the timeline, but not right away. This is because the set of boxes that the future versions came out of would be the only ones currently running, and the "earlier" versions don't know what would happen if they attempt to shut the boxes off and use them. When Abe and Aaron encounter a future Thomas Granger who has used one of their boxes, Aaron alludes to this risk/unknown situation:

"I say we shut it off and see if he [Granger]'s in there."

When Abe and Aaron do get the party right, they manage a way to get the boxes shut off without any trouble. They loop back one final time and stay isolated in a hotel room. This is where we see Aaron sleeping, and Abe unable to. In this timeline, their earlier selves perfect the party, then shut off the boxes and vacate the timeline, leaving Abe and Aaron to argue at the airport.

I believe that any set of Abe or Aaron that is interrupted by a set of their future selves would then concede control of the timeline to that future set, and then leave town (probably) and try and create their own destinies/futures, just as Aaron2 did.

This is strongly suggested by the final warehouse scene: there are two Aarons here, each in his own warehouse, each building his own big box. Aaron3 (or...Aaron23) has just perfected the party and is clean-shaven. Aaron2 has just left town and the party to Aaron3, and is not clean-shaven.


There is a rather crude way to get this done. We know that Aaron and Abe are both capable of drugging their alternate selves unconscious. One of them could use two boxes and repeat this dark ritual multiple times, and then clean up the mess.

  1. Start box A.
  2. Start box B.
  3. If you receive a voicemail from yourself saying 'mission is go', use box A and go to step 1.
  4. If you encounter yourself, ambush him. Make sure no one finds him before the party.
  5. Go to the party. If you like how the party turned out, go to step 7.
  6. Use box B and go to step 2.
  7. Use box A.
  8. Start boxes A and B (to keep up appearances). Hide and leave yourself a voicemail saying 'mission is go'. Stay hidden long enough to be sure your double has used box A.
  9. Go to the party and repeat your successful choices.

When you are done with all this, there is only one copy of you and no one actually got ambushed after all. Cool huh?

There are some finer points that would have to be worked out, like how to cleanly arrange the situation so the right people get ambushed, but this should get it done with no lasting mess.

It is plausible that exactly this happened off camera. And it is only necessary for one person (Aaron) to do the going back and the ambushing. Abe doesn't have to be in on the scheme - in fact he shouldn't be in on it. Each time Aaron just coaches Abe on what to do, and after it's done, Aaron gets back in the box.

  • That's very clever! I assume (7) is a precaution for if (8) fails? What would they do in this case?
    – shay__
    Dec 23, 2017 at 10:38
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    Actually I made a logical error. Fixed now, I think. But if your "final" party visit goes badly, you would need a third box like A to use as a failsafe, to be able to try again without having two copies of you in the final timeline.
    – wberry
    Mar 15, 2018 at 1:45

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