An American wakes in an English hospital, unable to remember anything prior to a recent car accident. With only a magazine photograph as a guide, and an unknown benefactor, he attempts to unravel what increasingly looks like a bizarre murder.

Sly and dry intelligence agent Harry Palmer is tasked with investigating British Intelligence security, and is soon enmeshed in a world of double-dealing, kidnap and murder when he finds a traitor operating at the heart of the secret service.