In a British disciplinary camp located in the Libyan desert during WWII prisoners are persecuted by Staff Sergeant Williams (Ian Hendry), who made them runup and down a sandy hill under the hot sun with full equipment again and again. This hill was artificially built and located in the middle of the camp for all to see.
Sergeant Charlie Harris (Ian Bannen) is a more human and comprehensive guard, but the chief, S.M. Wilson (Harry Andrews), refuses to disown his subordinate Williams.
One day, five new prisoners arrive. Each of them will deal in a different way with the authority and Williams' ferocity and when one of the prisoners drops dead of exhaustion, the other men mutiny.