Sergeant Joe Gunn and his tank crew pick up five British soldiers, a Frenchman and a Sudanese man with an Italian prisoner crossing the Libyan Desert to rejoin their command after the fall of Tobruk. They and the Germans are greatly in need of water.
Sherlock Holmes sets out to discover why a trio of murderous villains, including a dangerously attractive female, are desperate to obtain three unassuming and inexpensive little music boxes.