In the swamps of Louisiana, a man's body is found completely destroyed, seemingly chewed apart by an unknown creature. Medical investigator Sam Rivers is tasked with solving the mysterious murder, leading him to discover a darker secret lurking within the depths of the wetlands. With the help of biologist Mary Callahan, Sam uncovers a twisted tale of genetically engineered Chinese snake-heads, which have escaped their creator's control and are terrorizing the locals. As they fight for their lives, wealthy hunter Jeff arrives with his team, turning the predators into prey. Sam, Mary, and Jeff must now confront their worst fears and escape the deadliest game of cat and mouse before it's too late.