Hank (Paul Dano) is a young man trapped on what appears to be a desert island. The impression is that he's been there for a long time. Just as he's about to end it all by hanging himself from a rock ledge Manny (Daniel Radcliffe) washes ashore. Although Manny is a dead body he quickly becomes Hank's best friend. You see, Manny can do strange things, like transforming into a human fart powered water scooter and producing clean drinking water from his mouth. They soon escape the island and wash onto a new shore, where Hank and Manny live in the rocky woods and build structures and artwork out of garbage. Eventually they venture away from their hideout and find a woman named Sarah (Mary Elizabeth Winstead), whom Paul has a crush on.
This is a very weird, surreal movie, as if David Lynch wrote/directed WEEKEND AT BERNIE'S.