While traveling through the California desert for a business appointment, David Mann (Dennis Weaver) passes a smoky tanker truck. A game of cat-and-mouse quickly escalates into a life-and-death battle between David and the unseen trucker, with their vehicles as weapons. The film is based on a story by author Richard Matheson and co-stars Jacqueline Scott, Eddie Firestone, Lou Frizzell, Gene Dynarski and Lucille Benson.