The Executioner (1970)
The Executioner is a 1970 cold war spy thriller British film starring George Peppard as secret agent John Shay who suspects his colleague Adam Booth, played by Keith Michell, is a double agent. In the film, Peppard's character tries to prove the double role of his colleague to his spy-masters and when he fails to do so he kills him. It was produced by Charles H. Schneer for Columbia Pictures and filmed in Panavision and Technicolor.
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