Maurice Castle (Nicol Williamson) is a mid-level bureaucrat in MI6 whose life seems completely without peculiarity, peccadillo, or any quality to suggest he’s anything but a dull bureaucrat, except for the interesting, casually introduced detail that he has an African wife, Sarah (Iman (model)), and son, Sam (Gary Forbes). Meanwhile, the company regime, represented by corpulent, bluffly cheery Dr Percival (Robert Morley), who’s actually an expert in assassinations and biological toxins, and éminence grise, Sir John Hargreaves (Richard Vernon), advise newly appointed security chieftain Daintry (Richard Attenborough), they believe they have a traitor at the MI6 African desk. The duo determine the mole must be quietly killed, rather than be allowed publicity in a trial or a flight to Moscow. They quickly decide the most likely candidate for the traitor is Arthur Davis (Derek Jacobi), Castle’s playboy (lifestyle) office partner.