During the North African Campaign in the Second World War, Captain Douglas (Michael Caine) is a British Petroleum employee seconded to the Royal Engineers to oversee incoming fuel supplies for the British Eighth Army. Colonel Masters (Nigel Green) commands a special raiding unit composed of convicted criminals, and after a string of failures he is told by his commander, Brigadier Blore (Harry Andrews), that he must have a regular officer to lead a dangerous last-chance mission to destroy an Afrika Korps fuel depot, otherwise his unit will be disbanded. Despite Douglas's objections, he is chosen for his knowledge of oil pipelines and infrastructure. Douglas is then introduced to Cyril Leech (Nigel Davenport), a convicted criminal rescued from prison to lead Masters' operations in the field.