At a British military prison in North Africa during World War II, convicted British soldiers face harsh conditions and an even harsher staff. For Trooper Joe Roberts (Sir Sean Connery), reduced in rank from Sergeant Major, and imprisoned for striking an officer, the going is particularly difficult. Sharing a cell with four other men, they are under the command of Staff Sergeant Williams (Ian Hendry), a particularly cruel task master, who takes pleasure in imposing harsh punishment, especially making the men run up and down the "hill" until they collapse from heat exhaustion. No matter the excesses, the prison Sergeant Major will always back up his men. When one of the prisoners dies however, there is an opportunity to expose Williams for what he is.