A teenage fugitive with an incredible secret races to stay one step ahead of the mysterious forces seeking destroy him in this sci-fi action thriller. With three dead and one on the run, the race to find the elusive Number Four begins. Outwardly normal teen John Smith never gets too comfortable in the same identity, and along with his guardian, Henri, he is constantly moving from town to town. With each passing day, John gains a stronger grasp on his extraordinary new powers, and his bond to the beings that share his fantastic fate grows stronger.

The small city of Tarker's Mill is startled by a series of sadistic murders. The population fears that this is the work of a maniac. During a search a mysterious, hairy creature is observed. This strange appearance is noticed once a month. People lock themselves up at night, but there's one boy who's still outside, he's preparing the barbecue.

Marty (Alfred Molina) is a down-and-out jazz musician with colorful dreams of making it big, but right now he's living on the edge and making small money by giving music lessons to people who don't seem to want them.