Two sailors who are always competing against each other set their sights on the same girl. When she chooses one over the other, their friendship ends acrimoniously. However, things change when one the men is in a submarine trapped beneath the ocean and the other, a diver, is sent down on a rescue mission.

During World War I, a professional thief known as The Lone Wolf is assigned to steal a cylinder with important information from behind the German lines and bring it to Allied intelligence headquarters. However, German agents set out to stop him, headed by the man who was responsible for the death of the thief's sister.