A bunch of young people are invited to a Caribbean cruise on a gangster's yacht, to distract the attention of the authorities. Unfortunately, a mutant cat which escaped from a test laboratory also gets on board, and kills most of the passengers.
Dr. Madeline Faye, a successful psychiatrist and best-selling author, seeks refuge in her wealthy father's beach house while she works on her next book. She begins to suspect that a former patient is stalking her.