Viewers will probably start off just as confused as the main character, US army pilot Colter Stevens (Jake Gyllenhaal). His last memory was of being on an army mission, but Stevens suddenly finds himself on a train which is about to be blown up, and he now seems to be a teacher called Sean Fentress .
He learns that he is part of a version of events that happened earlier in the day, and that "Stevens" is already dead. In fact, the army is keeping his brain on life support so that he can travel into an alternate reality and stop the bombing, in an experiment called Source Code.
The travel between alternate realities will inevitably draw comparisons with Inception. While the complexity of Source Code's sci-fi plot cannot quite match the other, the repeated scenes of the train blast have an almost hypnotic effect.
Vera Farmiga is excellent as Colleen Goodwin, an army officer involved in the experiment. She effectively reveals Colleen's inner conflict, between her desire to let Stevens die - as he wishes - and her duty to follow orders.
Sadly, Michelle Monaghan's unemotional turn as Sean's girlfriend Christina is disappointing.
Although the ending is a little confusing, the suspense makes this an enjoyable watch.
DVD inc. science behind the film