This sequel finds Chief Inspector Clouseau (Peter Sellers) being summoned to the country of Lugash to investigate another robbery of the eponymous diamond. After developing some disguises, Clouseau embarks by plane and mysteriously vanishes en route. Hoping to solve the conundrum, enterprising journalist Marie Jouvet (Joanna Lumley) interviews those closest to Clouseau, including his father (Richard Mulligan), his boss (Herbert Lom) and his old nemesis, Sir Charles Litton (David Niven).