movie trailer (apple.com - quicktime)
NOTE: This spoiler was sent in by breadfan87.
Nicolas Cage is an obsessive compulsive con artist,
and his partner is Sam Rockwell. They pull medium level cons these days, and Nicolas has quite a large amount saved up from his years on the job. (He keeps some of the money in a plastic dog in his living room).
Eventually, his OCD gets a little out of control. His normal doctor is out of town, so he starts seeing a new shrink who gives him prescription pills for his anxiety.
A small subplot that is kept going throughout the movie is a supermarket cashier who he always gets his groceries from. There seems to be a mutual attraction but he is too awkward to act on it.
Somewhere in here he learns that he has a teenage daughter from his last real relationship from 14 years earlier. At this same time he and his partner are planning their last big con, or at least his last con. So, as they are getting close to his final mark, he is also getting to know his daughter (Alison Lohman).
They pull off the con, with the help of his daughter no less, and begin to celebrate. Nicolas and his daughter come home that night to find that the guy they conned is in the house and has beaten up Sam Rockwell pretty badly. He gives Nicolas an ultimatum: to give him a percentage of all his future cons, or his daughter dies. (This particularly sucks because Nicolas was retired as of this last job).
As he is making these demands though, the guy they conned is shot by the daughter who had run into the other room and gotten a revolver. At this point, they decide Sam Rockwell will take the daughter out of the state and Nicolas will meet up with them later after having taken care of the body.
He goes back into the house and makes his way to the living room, where the body is gone. He turns around and is knocked out just as he sees the guy he thought was dead coming at him.
He wakes up in a hospital where 2 cops are saying he's in a lot of trouble and are trying to find out where his partner and daughter are. He demands to see his doctor or he won't tell them anything. So, the doctor is brought in and left alone with Nicolas. Nicolas tells him he has to get to the secret stash he has in a safety lock box, and keep it safe. So he tells him the code.
The next time he wakes up the hospital is deserted, and his door isn't locked. He leaves his room and discovers he's on the roof of some building in the city.
When he gets home to check his smaller stash in the dog, he finds a note from Sam. It turns out that most everything in the movie was one big con on Nicolas: his daughter, the shrink, the mark, everything; it was all to get to the money he had saved over the years. He visits the wife he had left 14 years earlier looking for the daughter, but she's not there and he loses it and the screen fades to black.
ONE YEAR LATER comes up and we see that he is now a carpet salesman. By a freak coincidence, the girl who had conned him as his "daughter", comes into the store with her boyfriend. She says sorry and that it was a one time thing, and he lets her off the hook. We see why when he goes home to his wife, the supermarket cashier, who is now pregnant.