Charles Dreyfus, former Chief Inspector of the civilian police force, Sûreté, is declared sane by his psychiatrist and expects to reclaim his position after his impending release from the psychiatric hospital. He no longer goes into a homicidal frenzy at the mention of his nemesis, Jacques Clouseau, who was recently promoted to Chief Inspector. When Clouseau visits the hospital, Dreyfus is unable to retain his hard-won composure in the face of the inspector’s repeated, inadvertent assaults; Dreyfus relapses into insanity and vows to kill Clouseau. Later, Dreyfus escapes from the hospital and lies in wait at the apartment directly below Clouseau’s. Meanwhile, Clouseau enters his apartment, readying himself for a martial arts battle with his manservant, Cato. Dreyfus drills holes in the ceiling and watches Clouseau through a periscope. Cato attacks as Clouseau lays down for a nap, but the ensuing mayhem is interrupted by a phone call from Sûreté headquarters, informing the inspector that he may be in danger from the escaped Dreyfus. While Clouseau tries on his new Quasimodo costume, Dreyfus plants a bomb in the apartment, but the inspector is saved when he becomes airborne by the costume’s inflatable hunchback, allowing him to float out the window before the bomb explodes. Later, as bank robber Jean Tournier is escorted to prison, he is aided in his escape by Dreyfus, who flies the prisoner to safety in a helicopter. Dreyfus explains his plan to recruit the world’s greatest criminal minds and rob the Paris Credit Bank of $20 million. He then kidnaps Professor Hugo Fassbender and his daughter, Margo. The only witness to the kidnapping is the butler, Ainslie Jarvis, who was found unconscious at the scene. Clouseau meets detectives Drummond and Quinlan of Scotland Yard at Fassbender’s home, where the inspector interrogates the staff. No evidence is obtained, but Clouseau does succeed in damaging a priceless Steinway piano and accidentally shooting Drummond in the buttocks. Fearing an international incident, the British detectives are reluctant to notify the Sûreté of Clouseau’s incompetence. That night, Clouseau follows Jarvis to a gay nightclub, where the butler performs as a female impersonator. While the two men tango on the dance floor, a pair of Dreyfus’s henchmen force their way through the crowd, but are subdued by Jarvis and the patrons, before the club is raided by the police. Meanwhile, at the Moonshine Castle in Germany, Dreyfus forces Fassbender to build a doomsday machine. Sometime later in Washington, D.C., as the President of the United States, his German-born secretary of state, and several other colleagues watch a football game in the Oval Office, Dreyfus interrupts with a worldwide broadcast, demanding that the nations of the Earth make it their priority to kill Clouseau, or he will cause mass destruction with his doomsday machine. He plans to demonstrate it the following Saturday on the United Nations Building in New York City. After Dreyfus signs off, the President orders the U. S. intelligence community to find out who won the game. Clouseau returns to the gay bar, but finds Jarvis near death in his dressing room, where the inspector discovers a leaflet for the Oktoberfest in Munich, Germany. Believing it to be a clue to Dreyfus’s operation, he travels to Munich, determined to solve the case without any assistance from other agencies. On Saturday, the world witnesses the disappearance of the United Nations Building at the hands of Dreyfus, who demands that Clouseau be killed within the next seven days. When Tournier asks why killing one man would require such an elaborate scheme, Dreyfus explains, “The Doomsday Machine is a water pistol compared to the destructive power of Clouseau.” Following his arrival in Munich, Clouseau continues his investigation as assassins of all nations eliminate each other without harming him. Later, the President is awakened in the middle of the night with the news that twenty-six foreign assassins have been killed, leaving only the Egyptian and Russian agents. Meanwhile, Tournier, disguised as Clouseau, the Egyptian agent, and Olga, the beautiful Russian agent, all converge on the inspector’s hotel room. The Egyptian kills Tournier, unaware that he is an impostor, and seduces Olga, who assumes that she is making love to Clouseau. The Egyptian leaves, but Olga is still recovering from her moment of ecstasy when the real Clouseau returns. Several minutes pass before the inspector discovers the woman in his bed and the corpse in his bathtub. Olga identifies herself as a loyal Soviet agent who never had an emotional attachment to any man until this night. They examine the body in the tub, and Olga recognizes the Moonshine crest, which leads Clouseau to Dreyfus’s castle hideout. Dreyfus is overjoyed upon receiving word that Clouseau is dead, while at a nearby inn, the still-very-much-alive inspector rents a room and makes several unsuccessful attempts to break into the castle. Dreyfus’s call to the inn for a dentist results in Clouseau gaining access to the castle, disguised as Dr. Schultz. A mishap with a tank of laughing gas puts both men into hysterics, and after Clouseau removes the wrong tooth, Dreyfus realizes that his nemesis is still alive. While Dreyfus prepares to remove England from the face of the Earth, Clouseau stumbles through a remote part of the castle and is ultimately catapulted onto the barrel of the doomsday machine. Clouseau, Fassbender, Margo, and Dreyfus’s henchmen flee the castle when the machine begins to self-destruct. Dreyfus plays “Tiptoe Through The Tulips” on his pipe organ as he and the castle disappear. Upon returning to his home in Paris, Clouseau finds that Olga has outfitted the bedroom with an enormous Murphy bed and a sound system that plays romantic music. As the two lovers find each other across the vast expanse of bed, Cato attacks. The bed retracts, propelling Clouseau, Olga and Cato through the wall and into the river below.