Who killed Marius Steen, the theatre tycoon with a fortune to leave his young mistress Jacqui? And who killed Bill Sweet, the shady blackmailer with a collection of compromising photographs? Charles Paris, the middle-aged actor who keeps going on booze and women, takes to detection by assuming a variety of roles - among them that of McWhirter of the Yard! In that role he precipitates the crime; as one of the blackmailer's victims he finds himself in bed with the blackmailer's wife and he also has a small part in a horror film - The Zombie Walks - in which the murderer tries to shoot him. He eventually arrives at the solution via the petrol crisis and an abortive attack of German measles!