In a remote desert, Jack is on a road trip with his girlfriend and her daughter, a close friend and his son. When the group of vacationers stop by the side of the road, the friend's son is almost run over by a speeding Cadillac. The group later spots the distinctive car in front of a diner and confront its owner, the disarming, but psychotic Cliff. What ensues is a twisted series of frightening incidents down Highway 666, better knownas the highway to hell.