When Dr. Howard Latimer finds the German actress whom he had just met at the London Airport murdered in his flat, he is led into a world of murder, blackmail, and a fake passport scam.

An actress and an artist are linked by his brother to deadly smugglers sought by Scotland Yard.

A husband-and-wife detective team look into the murder of one of her friends, whose father--a prominent scientist--has been kidnapped. They find themselves up against a sinister crime organization headed by a mysterious figure known only as "Z".

A serial killer terrorizes London. Each victim is found with a telegram signed "The Marquis." There seems to be no other common thread between the victims, and Scotland Yard is baffled. Novelist and amateur sleuth, Paul Temple, is warned to stay away from the case, but he and his glamorous wife Steve can never refuse a good mystery.