When the Pink Panther diamond is stolen from a Lugash museum, the country turns to the man who once before returned the gem to their land: French police officer Inspector Jacques Clouseau (Peter Sellers). Clouseau immediately suspects the same man who took the gem before, Sir Charles Litton (Christopher Plummer), but Litton realizes that he is being framed and and travels to Lugash to find the real thief. Meanwhile, Clouseau travels to Switzerland on the tail of his wife Lady Claudine Litton (Catherine Schell) in hopes that he will lead him to her husband and the stolen gem. But also on the trail is Lugash security officer Col. Sharky (Peter Arne) and Clouseau's crazed boss, Chief Insp. Charles Dreyfus (Herbert Lom).