John Shay (George Peppard) is the secret agent working for Britain who suspects his partner Adam Booth (Keith Michell) is a double agent. He beds down with the man's wife Sarah (Joan Collins) to get information his girlfriend Polly (Judy Geeson) can't provide. His superiors don't believe John's accusations are justified, but soon he is shadowed by two mysterious figures. When Sarah ends up in bed with Crawford (George Baker), John knows Booth is a traitor. His suspicions grow when he is pulled off a planned mission after the incident in this boring spy yarn.