Colter Stevens, a US Army helicopter pilot whose last memory is flying in Afghanistan, wakes up on a commuter train. However, he discovers that he has assumed the identity of another man. 8 minutes later, the train explodes and Stevens finds himself in some kind of pod. He then talks to someone named Goodwin, who tells him he has to go back and find out who the bomber is. He is sent back to go through the whole thing again and attempts to find who the bomber is but fails. The bomb goes off and...