The Executioner (1970) [Re-Up]

Explosive international intrigue results when British Intelligence agent John Shay suspects Booth, a colleague, of being a double-agent. Although Shay's superiors warn him against an investigation, he travels to Greece and Turkey in order to check out his suspicions. There, Shay becomes involved with a beautiful woman who was once her lover, and is now Booth's wife. Before long, Shay realizes that he is being used as a Communist pawn, and has fallen into grave danger.