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.

An American is visiting Britain and finds himself in possession of a briefcase full of secret documents that the spies of many different countries seem determined to get.