In the remote swamps of Australia's
Northern Territory, a wild cow walks to the edge of the still water to drink but is suddenly attacked by a ferocious and powerful beast that violently drags it into the lake. American travel journalist Pete McKell joins a small group of tourists on a crocodile-watching
river cruise in
Kakadu National Park of Northern Territory, led by wildlife researcher Kate Ryan. Toward the end of the cruise, Everett spots a flare in the distance and the group heads upriver to investigate. As the boat moves forward, the passengers become anxious, the landscape becomes hostile and dense and the wildlife silent as if a threat were watching the boat. They eventually come across a half-sunken wreck. As the passengers are wondering about the origin of the flare, a big reptilian shadow beneath the surface crashes into the boat, damaging the side. Kate manages to steer the boat ashore a small island in the middle of the river. Kate realizes they are in the territory of a large crocodile and explains they must leave the island by nightfall, as the tide will start to rise and the island will be submerged. Everett who was unconsciously standing at the water's edge with his back to her, suddenly is killed, pulled into the water by an unseen predator. Two locals, Neil Kelly and Collin, arrive at the island but the beast upturns their boat; Neil swims to the island but Collin was killed immediately by the beast. As night falls, Neil carefully swims to the riverbank in order to string a rope between two trees, creating a
zip-line to allow the group to cross the river. Everett's wife Mary Ellen crosses first, only to freeze in fear halfway across. Allen, becoming impatient and hostile, takes matters into his own hands by attempting to get himself and his daughter Sherry across with Mary Ellen still on the line. While trying to secure the rope, Neil is attacked and killed by the beast. The tree holding the rope breaks and the three on the line fall into the water. They swim back to the island, but as Allen crawls up the shore, the beast quickly lunges out of the water and throws him back into the river, where he is killed. The beast is revealed to be a rogue, 7+ metre long
saltwater crocodile. Later that night, Pete suggests hooking the beast while everyone else swims to the riverbank; Neil's two dead birds replace Kate's dog named Kevin, the initial bait idea. After a long wait, the anchor is suddenly pulled and the group makes a break for the far shore. The beast eventually lets go of the bait, seizes Kate and drags her underwater. Pete hurries across the river with Kevin in tow and into the bush behind the others. As day breaks, Pete is forced to chase Kevin into the bush after he runs off. He falls down a narrow chute into a large cave, where he discovers Neil's mangled body. The cave is the beast's lair and the dog leads him to a severely injured Kate. Pete attempts to carry her out but Kevin runs off to the head of the cave, where he is killed by the beast hidden in the cavern. It climbs back onto a raised rock to finish devouring Kevin's torn corpse, before moving heavily to a corner to digest its meal. While the beast sleeps, Pete attempts to sneak out of the cave with the unconscious Kate, but the sleeping beast senses their presence and silently dives back into the murky water to attack Pete from behind, but narrowly misses. After several attempts on them both, the beast takes a chunk out of Pete's hand while he grabs a piece of bone and stabs one of the beast's eyes. Pete eventually props a large broken log against a boulder, with the sharp end pointing outwards, so when the beast lunges at him, it is impaled and killed. Pete escapes from the cave with Kate and finds the tourists and paramedics. A newspaper article later details Pete's heroic battle with the beast and rescue of Kate. ==Cast==