Source Code keeps you guessing as to what kind of movie it is until you're halfway through it, and that is just one of the things that makes it wonderful and heartbreaking.
Released in 2011, the hybrid action thriller thrives off misdirection. It hits you at first with the quotidian, a morning ride on a Chicago commuter train. That everyday experience is undercut by unease, in the form of the main character we don't know yet freaking out over where and who he is. When a fireball explosion rips through the train at 6:42, we're slammed with a set-up that's denied any resolution. By the time the science-fiction concepts start to get pop up seven minutes in, you already have the seeds of a mystery in your brain.
The film centres on Captain Colter Stevens (Jake Gyllenhaal), a soldier who's being sent into the body of Sean Fentress eight minutes before he dies in an explosion on a train. A secret military science program uses quantum physics manipulation to send Stevens' consciousness into Fentress' body, with the hope that the soldier can find a bomber threatening Chicago with a dirty bomb attack.
The big twist in Source Code is that Stevens is essentially brain-dead. He's not allowed any respite even in death. Stevens' consciousness is treated like machinery and his interactions with the other people on the train get cast as bloodless tasks that he should be executing dispassionately. But his humanity -- and the emotions tied to it -- is all he can cling to and the messiest part of the movie happens when he's manipulated into reliving the same tragedy over and over again.
Looking back at the movie with some distance, what stands out is how stridently political it is about the uses of human bodies and intrusive advanced technology in the new normal of the surveillance state. It's the classic "just because you can doesn't mean you should" scenario. Diving into the same quantum splinter of spacetime again and again, Stevens is a flesh-and-blood monitoring program, parsing interactions and personality quirks for clues to imminent catastrophe. He's a body thrown onto the grenade of fear, with the hopes that the sacrifice will save lives on a greater scale. The threat of the bombing looms over him but he's also trying to unravel the mystery that's got him locked in a cold, dark isolated space.
One of the reasons that Duncan Jones' film succeeds because it's got a playful, puzzle-like structure that reveals more horror as it goes along. Written by Ben Ripley, it reads as a deliberate riff on Groundhog Day, but the tighter loop and more macabre stakes energize it in a hypnotic way. The iterative accrual of situational knowledge is a strong thematic pull here, pinging off the desire that people have to re-do parts of their lives. We'd all do things differently if we knew we could avert or deflect a horrible outcome.
This gimmick lets Gyllenhaal shade his performance differently throughout the film. He throws bewilderment, know-it-all snark and desperation on his face with enjoyable aplomb. His counterpoint is Dr. Rutledge, the chief scientist played by Jeffrey Wright. Wright plays Rutledge as cold but not completely unfeeling; there's enough amorality in his performance to make you loathe him but that's leavened by the genuine worry in his voice when he talks about lives at stake. Vera Farmiga's Colleen Goodwin plays a crucial role in the middle of the poles represented by Stevens and Rutledge; she's the flickering humanity inside the military science mechanism and recognises that each soldier on the battlefield is more than just an asset to be deployed.
The love story that starts to bloom between Stevens and Michelle Monaghan's Christina Warren feels trite at first, a way to aim for a four-quadrant marketing angle to pull in more of an audience. But the tragedy of cyclical death adds a bittersweet tang to it and makes the movie's happy ending feel less obligatory and trite. Source Code is the kind of movie that deserves to be viewed as a classic in the grand tradition of science fiction: it speaks to its moment and reverberates forward, reminding us that our ability to create scientific wonders will be thrust into situations where we won't always want it to live.