Martin, Diana & Java are sent to a Caribbean resort where people have gone missing. They find that the resort is actually run by shapeshifting zombies who are sacrificing the vacationers to a sea creature called Hexan.

A couple sees a group of misshapen people (known as zombies) and they are not human. The gang investigates why people go missing while they are on the Caribbean Resort. They soon find out that there is an evil undead water monster from the Yellow Tide forcing the humans to worship him. A baptism ceremony invites a new worshiper to the master.