A man (Adrian Brody) wakes up at the bottom of a cliff, in a wrecked car, with no idea who he is. His leg is caught under the dashboard so he can't get out. And there's a dead body in the back seat. He comes across a credit card and thinks that's his name. But when he turns on the radio he hears a story about some local bank robbers--and they mention the name that's on the credit card. So he thinks he's one of them, especially when he has brief flashes of the incident. One of them involves a young woman, who shows up in the woods. At first we think she's really there but it's a hallucination as his mind tries to sort out what's real and what's imagined. There's also the possibility that she's his victim--and is a ghost out to taunt him.
There's also a cougar that's feeding on the dead bodies that were with him in the car, which gives him more of an incentive to get away. He manages to untangle his leg from the wreck but it's broken and he has to make a crude splint. A dog shows up, which offers him some companionship--and a silent figure who knows that the crashed vehicle is filled with cash almost shoots him.
It's always a challenge to make a movie interesting with only one character but this manages to do so, primarily because of Brody's anguished performance.