Source Code and Rubber

Crazy day. One minute you're in Afghanistan, fighting a war, the next you're on a commuter train to Chicago, sitting across from a woman you've never seen before who's nattering away like she knows you. She keeps calling you Sean. Which is not your name. Very strange. Then the train blows up.

Source Code is a tight little sci-fi thriller with a nice, knotty premise, and it does its job in a commendable 93 minutes. It's a lot of fun, and its time-crunching suspense, heightened by the efficiency of its execution—the nimble way it's been blocked, shot, and edited—sticks in your mind. The director, Duncan Jones, whose low-budget Moon was one of the niftiest surprises of 2009, has a natural facility for science fantasy, and here, given more money to work with, he brings off another small genre gem.

Jake Gyllenhaal is Colter Stevens, the man on the train, an Army helicopter pilot whose life only appeared to end in that fiery explosion. He subsequently finds himself someplace else, with a monitor near at hand on which an Air Force officer named Colleen Goodwin (Vera Farmiga) explains that Stevens has been on a secret mission into the very recent past—only a few hours previously—to find the bomb that blew up that train and, more important, the man who placed it onboard. The bomber, it seems, has planned an even more-lethal follow-up atrocity.

Stevens is still baffled. So Colleen's boss, a frosty doctor named Rutledge (Jeffrey Wright), joins her to help clarify what's happening. Stevens, it turns out, is part of a government experiment involving “source code,” a new technology that allows someone to be inserted into the mind of another person during the last eight minutes of that person's life. Asked exactly how this whatever-it-is works, Rutledge offers a timeless sci-fi explanation: “It's very complicated.”

The rest of the picture follows Stevens on repeated eight-minute missions back to the ill-fated train. Each time, hassling suspicious passengers and desperately searching for likely bomb-hiding places, he unearths a new clue. He also grows increasingly fond of the woman sitting opposite him, the bright, pretty Christina Warren (Michelle Monaghan). But his return visits are inevitably cut short by that ball of fire before he can solve the puzzle.

The structure of Ben Ripley's script, with its cuticle-chewing race against time, strongly recalls Alfred Hitchcock, as does Chris Bacon's nerve-pinch score, which is richly reminiscent of the master's favored composer, Bernard Herrmann. And what might have been a one-note tale blossoms with intriguing ramifications. Slowly falling in love with Christina, Stevens becomes determined to save her life. But Rutledge tells him he can't—she's already dead, the train having been destroyed a few hours earlier. (Here, in traditional sci-fi fashion, the story begins not adding up, but so what.)

Gyllenhaal, competent as always, gets solid support from his costars. Monahan, mainly confined to repeating the same lines of dialog each time Stevens revisits the train, radiates a beaming sweetness that grows on us as much as it grows on him—we understand his interest. And Farmiga, whose character is little more than a face on a screen, manages to convey deepening emotional shifts. But the sharp, tricky story is the real star here, and Jones, a director of clear gifts, knows just how to drive it home.