YouTube - Source Code - Official First 5 Minutes [HD].
"Source Code" is an ingenious thriller that comes billed as science fiction, although its science is preposterous. Does that matter, as long as everyone treats it with the greatest urgency? After all, space travel beyond the solar system is preposterous, and yet we couldn't do without "Star Trek." The "science" in this case is used to prop up an appealing story of a man who tries to change the past.
His name is Colter Stevens (Jake Gyllenhaal). That he is sure of. That's why it's strange when he finds himself on a Chicago commuter train talking to Christina Warren (Michelle Monaghan), a woman he's never met. It's even stranger when he goes into the toilet and sees a face in the mirror that doesn't belong to him. - rogerebert
I enjoyed this movie, but I don't think anyone needs to see the scene that shows the partial remains of the dead soldier with exposed intestines. Gratuitously gross.