In Source Code (major spoiler ahead):

Colter Stevens takes over the body of Sean Fentress. While it at first appears that he is only able to view the past, it turns out at the end that he is able to change it. At the end, Colter Stevens remains permanently in Sean Fentress' body. So does the real Sean Fentress no longer exist?

  • 4
    Great and often overlooked movie, btw.
    – DampeS8N
    Commented Feb 16, 2012 at 18:01
  • @DampeS8N: I agree and did you know that Source Code also a complete ripoff/homage of a Quantum Leap episode; which is why they got Scott Bakula to play Colter's father.
    – djm
    Commented Aug 7, 2014 at 16:55

5 Answers 5


All spoilers...

I think there are 2 timelines - one where Sean dies, and one where he ceases to exist as he's now possessed by Colter. Of course in the second time Colter exists twice. If they use him again in the same way there'll be a third timeline with 2 Colter 'possessions' and one comatose Colter. In fact each time they do it there will be another Colter possession, so if they use the technology to avert disaster regularly they will end up with loads of Colters wandering about.

  • This is a good answer but opens up even more questions, particularly your (spoliers!) last five words! Commented Feb 16, 2012 at 12:28
  • 1
    @Wikis What he's getting at is that Source Code is really a remake of Spartacus. ;)
    – user1027
    Commented Feb 16, 2012 at 15:45
  • 1
    @wikis This is what we like to call "room for a sequel"
    – DampeS8N
    Commented Feb 16, 2012 at 18:01
  • @RishabhPoddar - cheers for your opinion. It would be much more useful to know why; perhaps you could provide your own answer?
    – Keith
    Commented Apr 16, 2012 at 9:16
  • +1 After seeing the movie I pointed out to my sister that there was two copies of Colter's conscience in one timeline.
    – madth3
    Commented Nov 27, 2012 at 20:01

Firstly, I am not wild about the idea of a "real Sean Fentriss" (see below). Call Sean Prime the Sean Fentriss in the world the movie takes place in - the one where Source Code is being run to try and prevent a second terrorist attack. That guy is dead - the train exploded and he was on it.

What happens to all of the Sean Betas (and Sean Gamms, and. . . well see below)?

The answer to that is dependent on what you think is actually happening in Source Code.

Hypothetical model #1, which is pretty much what Keith described:

If you think that every time the simulation is run that a new universe is spun into existence, then Sean Fentress is probably ceasing to be once Colter "jumps in". The parameters for the creation of this universe are such that Sean Fentriss will never survive in it unless Colter alters the course of events - something he only manages to do once. Want to get freaky? Recall the end, where Colter-As-Fentriss (Sean N, if you will) calls that universe's version of the Source Code project and asks Veriga Farma to take care of that Coulter. We'll call him Coulter N. What if Universe N's source code project gets activated for another disaster down the road? The cycle repeats itself, only this time we're talking about jumping into some other guy. Paul Smithson. Paul N becomes a bunch of Paul N1, Paul N2 - Paul Gammas, if you will in the universes further spawned by activation of Source Code in Universe N. Paul's fate is the same as Sean's. He misses on all the future in every case.

Second Model:

If you think that what is happening is that Colter is actually appearing in a parallel universe, then Sean^N is definitely ceasing to be. But there are an infinite number of Seans out there. It holds that not all of them die on that train. In fact, there will be realities where that terrorist doesn't even exist. There may even be an intelligent cyborg-Dinosaur-Sean out there somewhere! Ok, I'm being silly on the last one. Anyway, any universe that Colter slides into appears to lose it's Sean. In most cases, that's because of the bomb on the train. But if Colter manages to stick around, I guess Sean ceases to be. Poor Sean!

In either case, I would consider all of these Seans "real".

I don't believe we have any real idea what is going on in Source Code (that is, I believe the movie leaves it up for us to decide what is going on); my own personal theory is basically Keith's. I really liked the movie though. I was expecting your basic action movie but got something more thoughtful.


If parallel worlds exists, there is unlimited options, and unlimited numbers of Seans with his different destinies..thats simplify answering.


There is too much parallel universe nonsense, so skip that. This is a government operation (no expense spared). Since in the end the train makes it through that changes what everyone thought from the beginning, that it was destroyed and all its passengers. So If we look at it Sean did NOT die on the train since in the end the event didn't happen. I am thinking that Sean was on the original train and did make it to Chicago and by some accident he winds up in a hospital with his body functions normal, but he is "brain dead". The government gets the body to use and makes the source code connection with our helo pilot who will now operate through Sean's body and temporarily is activating Sean's brain. The Question is, "does Sean have and memories of Christina before the time on the train?" If he has no memories, he was brain dead and what he knows comes from Coulter's brain, but the train memories comes from the "8 minutes" that were still left in Sean's brain after going "brain dead". This way we get rid of the problem of and X number of Sean's. Now going from the capsule to the train and back is apparently real, because Sean is able to leave the train at the end with Christina. Now that is a kind of teleportation mystery. Hmm, sort of like one of those "Somewhere in Time" things you mull over. Very good movie, Sci Fi without aliens, monsters , or dinosaurs. They should make more of these that get you to think, outside the box of 'Parallel Universe" that is used to explain away all things to simpletons"....a well, there was another superman who jumped universes and ..." So apply some physics, physiology, and see if you can find a good explanation in THIS world. MC

  • 6
    Welcome to SciFi.SE! You should break this up into paragraphs so it's easier to read. Right now, I can't tell exactly what your answer is.
    – F1Krazy
    Commented Jun 5, 2019 at 15:46

My answer can in no way be considered canon but is more or less my understanding.

In the movie Down to Earth:

Chris Rock plays a comedian who died before his time and was given a second chance in life in a different body. At the end of the movie though he stays in a different body but forgets everything of his previous life and his before-time death.

This is how I understand it happened. All in the same timeline with no different ones existing.

Also Source Code is a very underrated movie

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.