Very good science fiction thriller

Rating: 9/10 (7 April 2011)

Military helicopter pilot Colter Stevens (Jake Gyllenhaal) finds himself on a train, talking to Christina (Michelle Monaghan), who thinks he is someone else. After some minutes of confusing conversation, the train is involved in an explosion and crash, and Stevens wakes up in a capsule in conversation over a video link with Captain Goodwin (Vera Farmiga). It turns out that Stevens is involved in the Source Code project which enables him to be sent back into target Sean Fentress to relive 8 minutes leading up to the terrorist explosion, in order to find out who the terrorist is in order to prevent a second atrocity.
To thumbnail review this film, let me simply say that it is a superior science fiction suspense thriller. I thoroughly enjoyed it, and I recommend it.
I am now entering serious spoiler territory.
It doesn't take much to work out - as he does about halfway through - that Stevens is actually, to all intents and purposes, dead. It is made clear that his 8-minute trips back don't actually change anything - the atrocity has already taken place - but real time is slipping by, and the time left to apprehend the terrorist is limited. However, Stevens badly wants to save Chistina's life despite the fact that she is already dead.
This film has two endings. There is an ending which uses what is essentially a bullet time freeze frame tracking shot, and this is the ideal place at which to have ended the film: it is fair and faithful to what came before. And then a further end is tacked on. It's OK, I suppose, but the only way it works in the context of the science fiction explored in the earlier part of the movie is if it takes place in a parallel time line/reality. This has been mentioned, but not really put forward as part of the basis on which the plot stands and is therefore, I felt, slightly unfair. However, it is a happy ending for the masses, so I suppose one can't complain.
Even so, this is a pretty good movie - engaging, thoughtful and it has heart. All the principals are good.