Monaghan (left), stares into the eyes of a hand-cuffed Gyllenhaal

Us Rating: ***

In this complex, fantastical thriller, soldier Colter (Jake Gyllenhaal) gets an assignment: Figure out what caused a Chicago train to explode. Using a government experiment called Source Code, Colter enters the body of a commuter for the eight minutes before the bomb detonates. Once the train blows up, Colter goes back for the same period of time — again and again — until he zeroes in on the culprit. Further complicating matters: He falls for the chatty passenger (Michelle Monaghan) sitting across from him.

Though the story is overly intricate, Gyllenhaal does excellent work — showing once more that he can be a muscular action star, but also displaying emotional subtlety in the film’s quieter scenes. Monaghan feels relatable as a bubbly working girl getting increasingly frustrated with her new crush’s erratic behavior. Still, as the hero gets closer to finding the bomber, the plot grows even more far-fetched, and it unravels somewhat by the end. Give credit to the dashing and romantic Gyllenhaal for keeping this effort (mostly) on track.