When Evan was little he had problems with blackouts. There were no apparent reason for having this blackouts but after he moves from his home town the blackouts stop and when he grows older his life becomes better and better until one day he remembers what happened in one of the black outs. It happened when he read an old diary about that day. He soon relays that he can effect time by going back to the time he blacked out and change something. The only problem is that everything changes and his health becomes worse if he does it to mush and if he does a mistake when he goes back he might end up in prison when he wakes up and things doesn’t get better when one of his best friends form when he was a kid takes her own life.
The Butterfly Effect is a interesting movie with a interesting plot point. He wants to change something so badly but forgets the consequences.