The MacKintosh Man

Joseph Rearden, played by Paul Newman, is a petty criminal-turned-agent for British intelligence sent to infiltrate a Soviet spy ring in England by helping one of their agents break out of prison. He falls under suspicion and is forced to escape from his captors before making contact with MI5 officer Mackintosh (Harry Andrews) and Mrs. Smith, who assist him in uncovering the truth about the organization and its leader, Sir George Wheeler MP (James Mason), a Communist agent of the KGB. Rearden's efforts lead to a cat-and-mouse game in England, Malta, and Ireland, where he finally confronts his adversaries and discovers their true intentions.