Have you seen Memento? It's a murder mystery that scrambles time. Much better than The Matrix.

There are two interwoven threads in the film, one in colour and the other in black-and-white. The B+W scenes are in chronological order, the colour scenes run backward in time. Colour and B+W scenes alternate. They meet up at the end - the murder scene, which in any sane movie would be near the beginning.

The protagonist has lost his memory, as a result of a bang on the head during the murder; he has no idea what happened "before the beginning".