In the beginning of this movie a man, played by Jim Carey, changes trains on a sudden impulse. On the train he meets a young women played by Kate Winslet, they are attracted to one another immediately. They begin having an affair, but things don't go well. Carey's character decides to undergo a procedure to have his mind wiped free of memories. As this happens, we are brought into his mind as the affair between him and Winslet replays. We see how they meet and we watch the relationship desolve. The doctor who does the procedure is trying to see how much you a person can really forget. Even if memories are wiped, will people still be attracted to the same people?