When you die, the last eight minutes of your life remains electromagnetically imprinted in your brain. If you could inject someone into that persistent time memory and pull them back afterwards, you could send investigators into crises just before they happened and have them identify who committed the crime. It's a fascinating premise for a sci-fi thriller and director Duncan Jones pulls it off splendidly in Source Code.
Air Force chopper pilot Colter Stevens (Jake Gyllenhaal) finds himself in a commuter train heading into Chicago on a sunny Monday morning, chatting with attractive brunette Christine (Michelle Monaghan) who certainly acts as if she knows him. But he has no idea who she is, who he is, where he is and what's going on: his last memories were of flying a helicopter in Afghanistan. Christine refers to Stevens as "Sean" and says he's a school teacher. When he looks in a mirror, he's startled by the unfamiliar face that stares back at him.
Then the train is ripped apart by a bomb that kills everyone on board.
Turns out that Stevens is part of a top-secret military operation called Source Code and, as he gradually learns from his handler Colleen Goodwin (Vera Farmiga), he's going to be sent back to relive the same eight minutes prior to the explosion again and again until he can figure out where the bomb was and who planted it.
There are a lot of sci-fi action films that fall apart by the last reel, films that tax your ability to suspend disbelief until by the end you're just glad to get out of the theater (think of the recent remake of The Day The Earth Stood Still for an example). Source Code holds together remarkably well, with its slick design, constant twists and surprises, and a bad guy who wasn't at all obvious when we try to identify them along with Colonel Stevens. The story makes sense and while the end was a bit melodramatic, it was a satisfying, philosophical ending with a neat twist.
The handwave explanation for what doesn't really quite hold together as a scientific explanation is that the electromagnetic imprinting is something to do with "quantum physics". Dr. Rutledge (Jeffrey Wright), the amoral scientist in charge of the Source Code project, explains to Stevens that the experiences he's having are within the framework of that eight minute window, but that any changes he makes cannot affect whether people die or not: it's a sort of parallel universe. Except for when... well... whatever. Don't see this film with a physicist and you'll be able to just accept the internal inconsistencies of the premise without any further worries.
There are shades of a number of other sci-fi films that appear in Source Code too, notably a subtle reference to the brilliant brainwashing movie The Manchurian Candidate, where a combination of playing cards and specific words change what the person is thinking. In this case, a sequence of displayed playing cards and an audio soundtrack of an owl are "thread one" and "thread two" and are used to bring Stevens back to the present, where he's trapped in a strange, grungy almost post-apocalyptic capsule, talking to Goodwin's image on a small video monitor. Shades of Twelve Monkeys.
Stevens (Jake Gyllenhaal) talks with Goodwin (Vera Fermiga) in "Source Code"
The most obvious comparisons are with the Denzel Washington film Deja Vu (which also involved a military project to go back in time and find a train bomber, but in New Orleans) and the film Vantage Point (in which an attempted assassination is relived multiple times, but through differing perspectives). Source Code works better than either of these, however, with a more compelling story, more logical premise, and more satisfying ending.
There's a sense of brute-force aggression in the investigative technique that Stevens uses on his repeated journeys back to the time immediately prior to the train explosion, which make sense as he's a chopper pilot, not a detective. Each time he goes back, however, he remembers what he's learned in the previous trip. It's fascinating to watch him build a profile of the train passengers, trying to identify who is the bomber, and when he assaults people, convinced they're the one, it's understandable even as it's also sometimes shocking.
There are some very interesting special effects in the film too, effects that initially seem like flashbacks and Stevens diving into the pool of "Sean"s memories, but pay attention, there's much to learn by focusing on what he's seeing as the film unspools. As we'd expect, the Source Code process starts to break down and the slow reveal of what's really happening is chilling, though not played up as much as it could have been.
As Bill Murray explored so thoughtfully in the comedy Groundhog Day, there's something compelling about the idea that we could go back in time and experience something more than once, trying different actions and seeing how they affect the outcome. The inevitable question of which of those alternative realities is actually our own reality? That's part of what makes it an interesting subject to explore.
This wasn't a perfect film by any means. There are some daft effects, story holes, and inexplicable twists, but I found Source Code to be a cerebral and very enjoyable sci-fi thriller. It's no surprise that it's from Duncan Jones, the same director who brought us one of the best sci-fi films of 2010: Moon. This one's another winner. Go see it.