Military man Colter Stevens (Gyllenhaal) is a stranger on a train, but the beautiful woman (Monaghan) across from him is acting like he's an old acquaintance. "I took your advice," she says, as Colter looks around with paranoid suspicion. She calls him Sean. He catches his reflection in the window---it looks nothing like him. Why is he here? Colter/Sean tries to get his bearings, to suss out the truth from the multicultural mix of passengers around him. But a massive explosion ends his inquiry midsentence. And then he wakes up...sort of.
Part of the fun of Duncan Jones's frequently clever sci-fi thriller is being as in-the-dark as the film's protagonist. So without going too much further into detail, let's just say that Colter's a man on a mission involving a ticking time bomb, a repeating eight-minute virtual simulation and a top-secret mind-melding program called Source Code. His only aid is a stoic gal in uniform (Farmiga) who occasionally appears to him on a TV screen and doles out scraps of information that mostly serve to cloud his true purpose.
Use your imagination from there. Jones certainly does, working overtime to keep all the narrative's spinning plates in the air. There's even a cheeky, somewhat apocryphal montage of Colter continually failing at his assignment---the exploding bomb acts each time as a grimly funny punch line. It's as if Jones knows Source Code can't help but go off the rails---which it unfortunately does via half-baked Inception-style theatrics and some treacly all-you-need-is-love moralism. What begins as a tense, inventive suspense film becomes, to paraphrase Doctor Who, a wibbly-wobbly, timey-wimey, mushy-wushy mess. That's decidedly not fantastic.
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