Source Code (2011) : Movie Plot Ending Explained

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Source Code is a “repeating loop” Science Fiction film directed by Duncan Jones whose earlier film was Moon. Jake Gyllenhaal, Michelle Monaghan, and Vera Farmiga play the lead characters. It even has Russell Peters in a guest role. Unlike Moon, Source Code is a fast-paced thriller. The film follows a man who is made to go through an 8-minute window repeatedly to locate the person responsible for a train bombing. As the loop repeats, the plot thickens and I really can’t say more without giving away spoilers. Do watch this film before reading further. Hi, this is Barry and here’s the film Source Code explained, spoilers ahead.

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Here are links to the key aspects of the movie:

Source Code: Plot Explanation

What’s up with the train?

A train heading to Chicago was blown up and is suspected to be the first in the series of bombings that will happen. The next one is deemed to be in Chicago and they need to find out who is behind this and put a stop to it.

Who is Captain Colter Stevens?

Captain Colter Stevens (Jake) is a helicopter pilot that is stationed in Afghanistan. Colter gets hurt pretty bad in battle. When I say hurt pretty bad, I mean only his torso remains with no hands. Pretty Bad. Colter is practically dead. But the scientists at CAOC-N manage to preserve his brain, a part of it is kept functioning hooked to the Source Code.

Dr Rutledge source code ending explained

What is the Source Code?

Over 2 months, the scientists have been integrating Colter’s brain with a software called Source Code. The main guy behind Source Code is Dr. Rutledge. Here’s the theory – when a person dies, they can retrieve the last 8 minutes of memory from the brain post death. The Source Code is a virtual world which is injected with the memories of the people from the train through post-mortem. Using this software they can insert Colter’s consciousness into another person’s mind in the virtual world. Captain Colleen Goodwin (Vera) is part of the Source Code team and is the interface to Colter. The Source Code program loop terminates at the point of death of this person. On that train, everyone dies because of a bomb explosion and is the point when we see the Source Code terminating many times. They plan on using the Source Code to identify the bomber to stop further bombings.

Who is Sean Fentress?

Sean is a teacher. He is simply one of the travelers on the train who got killed. Sean is physically most compatible in terms of gender, body-size, and synaptic maps with Colter. Hence he is picked to download Colter’s consciousness into. We are not given any backstory as to who Sean is and what he’s doing with Christina.

Who is Christina Warren?

Christina (Michelle) is a woman is traveling with Sean to Chicago, who also dies in the bombing. While we are not given any backstory as to who she is either, we are shown enough to say that she has met Sean recently and both of them are interested in each other.

Who is Derek Frost?

He’s the dude who’s placed the bomb on the train. He’s the guy responsible for the death of everyone on that train. He also leaves behind his wallet intentionally to give the impression that he was on the train and was killed too. Derek gets off at a stop just before Chicago and uses a cellphone call to detonate the bomb. He also uses the cell phone detonation so that he can time it destroy another train passing by. Just more destruction.

Why is Derek blowing up stuff?

Derek is an end-of-the-world apocalypse nut. He believes – “The world is hell. But we have a chance to start over in the rubble. But first, there has to be rubble”. Like I said, apocalypse nut.


What is the Capsule Colter is sitting in?

In reality, Colter is in a medical tank with just half a body, he’s mostly dead. This capsule that we see Colter in is merely his brain trying to make sense of being wired to a computer. Whatever Colter is saying from within the capsule are just thoughts that are being interpreted by a computer and printed on a screen.

How can Colter see Colleen and Dr. Rutledge?

There is a video camera kept outside. The visuals from the video camera are being fed into Colter’s brain. His brain then, in turn, perceives it as a screen inside the imaginary capsule.

To summarize, Colter was nearly killed in Afghanistan. After that, he was hooked to Source Code. 2 months later a nut by the name of Derek blows up a train. Everyone on the train dies. The last 8 minutes of info is used from autopsy to load up the virtual world of Source Code. Colter is linked and sent into Sean’s consciousness to looks for the bomber in the simulation. Once Colter identifies the bomber, they plan on stopping him from further bombing places in the real world.

Now, let’s walk through the various loops inside the Source Code.

Loop 1

This is the first loop that we are shown in the film, there have been ones before but unsuccessful. Colter wakes up as Sean. He’s just dazed and confused. He goes to the bathroom to see that his face is not his. The wallet is not his. He’s trying to figure what’s going on. Christina tries to calm him down. The bomb goes off.

Colter wakes up in his capsule (the one his brain is imagining). He’s too disoriented. Colleen calms Colter’s mind down by giving information to remember and recall. While he seems to not know Colleen at first, he eventually recalls her. This is because this is not the first loop for Colter. He’s had a few before this on the train but is still getting used to the process of being put in and taken out of Source Code. Colter in his “capsule” doesn’t know he’s dead yet. He wants to talk to his dad. Colleen doesn’t give him any information and puts him back into Source Code.

Sean Christina

Loop 2

Colter has memories of the first loop and notices that the conversations change based on how he reacts. Colter marvels at the details of the simulation he is in. He thinks it’s a test and Christina is just the distraction. Colter sees someone drop their wallet and someone else returning the wallet. The guy who drops his wallet is Derek and he’s doing this intentionally. No one knows this yet. Colter locates the bomb in a bathroom. He comes out and fakes being transit security. Before he can do anything worthwhile, the bomb goes off.

Colter is back in his “capsule”. He wants to know what this is all about. He still thinks that he was in Afghanistan a day before. Colleen tells him that he has been with them for 2 months. Colter can’t remember because he’s nearly dead and not making any sense of his memories. Colter demands to know more before he can continue. Colleen tells him that he’s in a simulation that has been created out of a real-life event and he needs to find the bomb and sends him back in.

Loop 3

Colter believes that Christina is a real person and not just a simulation. However, Christina in the real world is dead. Colter gets to work to assess people. He even tries to use Christina’s help. He convinces her to get off at the stop before Chicago. Colter follows a guy who suspiciously exits the bathroom on the train. He’s just a guy with motion sickness. Colter suspects him to be the bomber and starts fighting him demanding his phone. As they fight, the train explodes in the distance. Colter realizes that he is suspecting the wrong guy. In self defense, the guy kicks Colter onto the tracks of an approaching train. Colter hits his head on the track and tries to get up, but is hit by the train and killed.

Colter has exited the Source Code in a way different from the bomb explosion. Therefore his mind is back to this imagined capsule but is unable to communicate with Colleen and the heating system seems to be turned off in the capsule. This is an indication that Colter’s mind is misplaced and the cold shows that he’s dying. He starts looking for a way out. He manages to fix the power unit. This simply shows that this brain is fighting death and is able to get back and communicate outwards. He explains to Dr. Rutledge that his “capsule” lost power. That’s when the team on the outside even realizes that Colter is perceiving himself in a capsule. Colter says that he saved a woman. Dr. Rutledge explains that saving anyone inside the simulation is counterproductive because in the real world they are already dead. They show him proof. He explains that Source Code is not time travel, it is an alternate reality that exists for 8 minutes of Sean’s last moments. Colleen tells Colter that on the upper deck of the next carriage, there’s a conductor’s compartment which contains a gun. She sends him back in.


Loop 4

Colter goes to get the gun but is stopped and tazed by train authority. He’s handcuffed to a pole. He can’t do much, the bomb goes off.

He tells the team that the gun wasn’t a good idea. Colter asks Colleen if she has ever been in Source Code. She says she hasn’t because he doesn’t fit the specifications. What she means is that you should be nearly dead to be a candidate to enter the Source Code. He’s sent back in.

Loop 5

Colter gets Christina to check on information about Captain Colter Stevens. He lies saying it’s an old friend. Remember, Christina thinks she’s with Sean. She knows nothing about Colter. She doesn’t know she’s part of a simulation. So she goes away to look upon the Colter. As it would be, the Colter from within the Source Code, too, has died in Afghanistan 2 months ago. Christina finds news articles about this on the internet. Meanwhile, Colter is suspecting the wrong people and trying to find the trigger to the bomb. He sees a lady with a Walter Reed bag (medical facility). He goes up to her and asks what CAOC-N stands for (he sees this on Colleen’s seat earlier). She says it’s the Air Force, and the “N” stands for Nellis. He borrows her phone and tries to call Dr. Rutledge (this is the Rutledge from within the Source Code). By then, Christina returns and says that Captain Colter Stevens was killed in action 2 months ago. Colter (Sean) can’t believe this info. According to him, he is still alive and in a “capsule” in the real world. The bomb goes off.

Colter fades in and out of many memories of the war and being fired upon. He asks Colleen if he is dead. She avoids answering him. Eventually, she says that part of his brain remains activated. She adds that what he’s seeing is a mere manifestation. It’s just his brain’s way of making sense of all this. Colter realizes that he’s imagining the capsule. Once he does the shape and size of the capsule magically changes. Now remember, the capsule is not part of the Source Code. It is merely what Colter is imagining inside his mind. This capsule is his representation of all that is left functioning inside his brain. Dr. Rutledge tells Colter to focus on the mission and stop getting distracted. Colter says he called Dr. Rutledge from the train. Dr. Rutledge only explains that inside the Source Code “another” Dr. Rutledge would have received the call. In the real world, there was no call. Dr. Rutledge tries to give corporate buillshit to Colter by saying this is a chance to serve his country in spite of death. Colter snaps back saying any soldier would say one death is enough service. Dr. Rutledge offers Colter death on completing the mission. Here we are shown that Dr. Rutledge doesn’t really care for anything but his program. They send Colter back in.

Further Loops

Colter tries and tries again but is constantly unable to find the bomber as there are too many people on that train. Colter is distracted and disoriented. He feels he can’t do this. Dr. Rutledge plays Colter a recording of his dad’s voice talking proudly about him post his death. While parts of Colter are kept preserved, the official statement to the world is that he died in battle. This is why his dad thinks he’s dead. Colter asks to be sent back in again.

The Second last Loop

Colter goes gets the gun and takes out the phone from the detonation device. He makes a call. He sees someone talking on a phone. Colter mistakes him to have picked up the call. He holds the guy at gunpoint. This guy is a regular software engineer talking to his wife. Colter says that he is going to hit redial on the phone and if the guy’s phone rings, he would shoot him. As expected, there is a ringing sound elsewhere else. Colter apologizes and follows the ringing. He sees a guy being handed his wallet from whom the ring sound seems to be coming. This guy is Derek. Derek goes to another compartment, drops his wallet and leaves. Colter goes to the compartment and finds Derek’s wallet. He realizes what’s going on. But the train doors close and it beings to move. Derek jumps off the moving train. He follows Derek to his van and confronts him at gunpoint. Derek seems completely unaffected and shows Colter the nuke he’s planning to blow up next. Derek has a concealed gun which he uses on Colter. Colter falls to the ground. Christina finds her way by stopping the train too. Derek shoots her. He confesses to being an apocalypse nut to Colter and drives away. Colter sees the train blowing up in the distance and Christina dies from bullet wounds.

Colleen source code ending explained

Source Code: Ending Explained

Colter tells Colleen that he has the name of the bomber and the number of his van. They send a unit to locate the van in the real world. Colter requests that Dr. Rutledge lets him inside Source Code one more time. Colter finds that world real enough to try and save those people. He says that there must have been a second cell phone that caused the detonation. In the real world, they track down Derek and the van before he can blow up his second bomb in the city. The Source Code program is a success. Everyone celebrates. Colter begs to be sent back into the Source Code. Colleen agrees saying that she would terminate his life support after Source Code’s 8 minutes. She sends him in. She goes to talk to Dr. Rutledge. He is in self-awe and wants to wipe Colter’s memory and start over. She says that they promised death to Colter. Dr. Rutledge doesn’t care for that promise, he is only interested in his program. She is not happy about this. She goes back and locks herself inside the unit where Colter’s real body is. This is when we are shown the partial remains of him connected to a machine for the first time. As promised, after the 8 minutes of Source Code, she shuts down his life support. She lets him die in the real world. Dr. Rutledge looks on furiously but us unable to get in.

Remember, Colter’s mind has already been linked into the Source Code. Here’s what happens in the final run.

Final Loop. Life within the Source Code

Colter wakes up and asks Christina to skip work and spend the day with him. She agrees. He goes on to get the gun and remove both cellphones from the detonation device. He stops Derek from exiting the train at the stop before Chicago. He removes Derek’s concealed gun and cuffs him to the pole. He shows Derek both the phones from the detonation device and his dropped wallet. He calls the authorities from Derek’s phone and confesses to his crimes and gives the location of the van. After this, Colter calls his dad posing as a friend of Colter’s and makes up. Colter gets back to his seat, makes peace with everyone around. He takes Christina out and kisses her at the end of the 8th minute. The bomb doesn’t go off this time, obviously. But what does happen is that time proceeds past the 8th minute in the Source Code.

What Source Code has done is created altogether a new reality. In the previous loops, these realities were ended because the bomb on the train killed Sean. So the alternate realities were created only for a window of 8 minutes. This time, there is no detonation, Sean lives on and hence Colter’s mind lives on as Sean inside the Source Code. He begins his new relationship with Christina. However, poor Sean mind is removed from existence inside the Source Code.

Colter, inside the Source Code, sends an email to Colleen from inside the Source Code. The email reads this:

At some point today, you’re gonna hear about a failed terrorist attack on a commuter train near Chicago. You and I kept that bomb from going off. An attempted bombing on a CCR train outside Chicago. But it was thwarted, and the suspect was found on board, named Derek Frost.

Colleen confirms this attempted attack and the name. She reads on.

If you’re reading this e-mail, then source code works even better than you and Dr. Rutledge imagined. You thought you were creating eight minutes of a past event, but you’re not. You’ve created a whole new world. Goodwin, if I’m right, somewhere at the source code facility you have a Captain Colter Stevens waiting to send on a mission. Promise me you’ll help him. And when you do, do me a favor. Tell him everything is gonna be okay.

We are shown Colleen looking at the body of a Colter Stevens who is kept on life support. This is the Colter Stevens, mind and body (whatever left of it) in the final run of the Source Code. In this reality within the Source Code, there was no explosion hence Colter Stevens from this reality is not being used for any mission yet. Effectively what we are looking at here is a Source Code within a Source Code and so on. We can only hope that in all the realities that get created, Colleen will be there to put an end to it.

What is to say that the “real world” that we have been shown all the while wasn’t a simulation itself? Well, the answer is, there is no proof. The “real world” too could potentially be just a simulation world within a Source Code program but then that would also make the movie have no real point.