A group of tourists on a cruise through Southeast Asia enter mysterious waters. A massive mutant monster lies beneath the surface, attacking the cruiser and killing passengers under mysterious circumstances. Among the tourists is a mysterious figure that may or may not be involved in the bizarre killings. The survivors flee to an uninhabited island, only to encounter a fiercer mutant. The survivors must band together to survive the monster and the elements, battling both beast and nature in a fight for their lives.