At a quiet resort on the French Riviera Anthony Tolworth, companion and agent of the exiled king of Althenia, lands from the King's yacht in his search for entertainment and remuneration for the Royal household, but he meets a corpse on the beach in front of the Casino. He tries to solve the crime himself before the police can - who suspect the woman, Eve Raymond, with whom he is in love. He enlists the help of his headmistress aunt and two interfering and typical small boys. But the machinations of local politics, not to mention Althenian affairs, make the task almost impossible.