A fishing community on a remote Maine island finds itself suddenly cut off from the rest of the world after the ferry stops coming. When people start to vanish, the terrified survivors realize that someone - or something - is hunting them.

Following a mental breakdown, a young woman must return home to Maine for treatment. After she is unwillingly thrust into nature, she finds unexpected solace in the company of a neurotic Park Ranger, who is dealing with issues of his own.