Lt. Cmdr. Tom Jeffords is an American commander serving under the British Royal Navy in 1942. He is assigned to blockade the island of Malta and told to formulate a plan to destroy the Nazi arsenal in Sicily. To do this he hits upon the idea of using a captured German "E-boat" to sneak through enemy lines and blow up the arsenal. Crew member Cmdr. Ashurst, though he has personal differences with his commander, volunteers to pilot the small torpedo boat and complete the mission, which is eventually accomplished.