Pete McKell (Michael Vartan), a cynical American travel writer, joins a disparate group of holiday-makers on a river cruise through the waters of Kakadu National Park. After an uneventful day cruising the river, the tour captain Kate (Radha Mitchell) is reluctantly persuaded to steer their boat into unexplored territory. They discover a secluded lake but terror strikes when their craft receives a powerful blow from beneath the murky depths and begins to sink. With little choice, she beaches the vessel on the closest dry land--a tiny mud island. With a rising tide and only half an hour of daylight left, fear grips the group as they realize they are trapped in the lair of a 'rogue' crocodile, governed only by its need to hunt and kill.