After losing a submarine and fifty crew in a battle with a German ship during WWII, a Royal Navy officer gets a second chance in a daring raid with midget subs.

Johnny Flanagan did not have the privileges of a good education or wealthy background but the streets developed his natural talent to be a great fighter. His enormous potential to reach the top is born out of a string of spectacular successes. All of which is brought to a halt when he develops a physical relationship with his manager's wife, the beautiful but manipulative Lorna. His naive temperament is no match for her callous, dispassionate scheming and he unwittingly becomes a pawn in Lorna's ultimate plan to murder her husband.

In Mexico, a financier on the run poses as a man he just murdered, only to find out that the man was also a murderer.