Plot

A group of teenagers are menaced by a driver-less train in the Australian outback.

The teenagers Marcus, Liz, Craig and Nina are camping in the remote outback of Australia. While driving on the road, a road train crashes on their car that leaves the road in a serious accident. The quartet survives and Craig breaks his arm, but their car is totally wrecked. However they see the train truck parked on road and Marcus and Liz walk to the vehicle to ask for help. They do not find the driver and soon Craig and Nina arrive. When they see the driver shooting at them, they decide to carjack the road train. Soon they begin to act strange possessed by some evil force.—Claudio Carvalho, Rio de Janeiro, Brazil

Marcus (Xavier Samuel), his best friend Craig (Bobby Morley), and their friends, Liz (Georgina Haig) and Nina (Sophie Lowe) are driving through the Australian outback, when a road train comes up behind their SUV and pushes them off the road, breaking Craig's arm. The truck stops some distance up the road. The group approach it, but the driver is nowhere to be found. Distant gunshots are heard, and a crazed figure in the bush screams and runs towards them. Panicked, they commandeer the truck and drive away. The truck's radio turns on by itself. After all four fall asleep, the truck drives itself off the road and up a hill. When they wake up, Nina looks after Craig while Liz leaves to search for a shack she's seen. Unable to start the truck, Marcus accompanies Liz.

Nina discovers the truck's fuel tanks are empty, but finds a large pipe underneath the trailer, filled with a mysterious red fluid. Craig, tormented by visions of the hellhound Cerberus, finds a key to the trailers. He opens and enters the rearmost trailer, only for the door to close itself behind him. Marcus and Liz have a disagreement over her having slept with Craig, causing Liz to storm off. Marcus stays on the road and has a run-in with the truck's driver, who shoots himself. Liz locates the rundown shack, where she finds unlabeled cans containing the red fluid. Thirsty, she drinks some, but quickly runs back to the truck after finding bloody remains.

Liz and Nina try to start the truck, but Marcus, now bearing the driver's clothes and gun, tries to destroy it. The women overpower and tie him up. Craig emerges from the trailer and kills Marcus. The truck starts up again, and Nina tries to back it up. Liz stands at the rear to signal Nina, but eventually leaves to drink more red fluid. Nina, unable to see Liz, exits the cab and sees Craig, who tries to lure her into the rear trailer. Hearing Liz crying for help from inside, she pushes Craig in and locks the door. Eventually, after Nina turns the truck around, she stops and examines the front trailer. To her horror, she discovers it is an abattoir where human bodies, including Marcus's, are ground into the red fluid that fuels the truck. Shocked, she returns to the cab and keeps driving.

Nina spots a car and signals them for help. The truck radio turns on again, distracting Nina long enough to allow Craig and Liz to break into the cab. As the three fight, Craig rams the truck into the car. Liz is thrown from the cab by Nina, who is then knocked out. When Nina awakens, she finds Craig dragging Liz's body to the trailer. He tries to persuade her to help, rambling of a "magnificent opportunity". Nina instead flees, but Craig slams her head on the side of the cab. He drags her into the trailer, but she manages to defend herself and flees into the bush. Craig pursues and catches Nina, but she kills him with the truck driver's gun. As Nina emerges from the bush, she spots the couple from the wrecked car examining the truck. She runs toward them, screaming warnings. The couple, having been run off the road, hearing distant gunshots, and seeing a screaming figure running towards them, commandeer the truck and drive off, leaving Nina to watch in horror as the bloody cycle repeats itself.