Movie Story : When a man's body is discovered mangled beyond recognition in the Louisiana swamps, medical investigator Sam Rivers is assigned to find his killer. Teaming up with biologist Mary Callahan, he travels to the victim's floating home and meets the family and friends who lived alongside him. They soon uncover that genetically engineered snakehead fish, owned by a wealthy hunter, are attacking and killing the local residents. As the group struggles to survive, the hunter Jeff arrives with his crew to track down the creatures.