A 1971 espionage thriller trying for a Le Carre-type impact but ending up pretty lame. Armstrong is high up in British Intelligence and is central to a never clearly defined operation (Sonntag) which is an excuse for higher-ups, a very stereotypical lesbian and a disgruntled careerist, one of whom is a spy, to undermine him. A young woman whose agent fiancée is killed early and a German journalist are part of incidents on both sides of the Wall before the story fades but some characters, including an East German spy, are quite well realised.