This rarely shown, spy-coming-in-from-the-Cold-War film was directed by Sidney Lumet from a John le Carré novel, and stars James Mason and Simone Signoret. British critic John Gillett writes in Sight and Sound, “Most of the drama takes place in suburbia or gritty little offices--Hitchcock territory almost (notably the murder in the theatre scene), with Paul Dehn's concise, urbane script...making the most of a good story and deviating little from John le Carré's original. This time the investigator is middle-aged and burdened with a promiscuous wife; his crisis comes when he discovers that a wartime comrade has moved to ‘the other side.' Sidney Lumet brings to the material not so much a personal style as a kind of reliable American narrative sureness which allows the spectator to sit back and let the story exert its grip.... With Simone Signoret's appearance, the film makes its most serious jab at the contemporary conscience. War-torn, soiled and now betrayed, the character comes painfully to life as Signoret, majestically calm in Lumet's big close-ups, pours out her bitterness to James Mason's weary, insecure investigator....”