A string of robberies has occurred in Britain and it's up to Inspector Clouseau to catch the criminal.
Detective Inspector is borrowed from the Surete on special assignment for Scotland Yard in hopes that a fresh outlook will help the government recover the loot from the Great Train Robbery, which is being used to underwrite a new crime wave. What they don't count on, however, is having more than one Closeeau on the job.—[email protected]
In London, Sir Charles Braithwaite, Commissioner for Scotland Yard, struggles to solve an organized crime case involving a gang which has been performing robberies across Europe. Suspecting a mole within Scotland Yard, England's Prime Minister decides to request outside help to solve the case, which the press view as an insult.
The Prime Minister brings Clouseau (Alan Arkin) in to solve the case. Commissioner Sir Charles Braithwaite (Patrick Cargill) heads the Scotland Yard & considers this a slap in the face to the organization. Clouseau is his usual bumbling self and is never far away from an accident. Shockley (Richard Pearson) is assigned to assist Clouseau.
Charles believes that the latest 2.5 MM pounds stolen by the gang are being used to plan something much bigger and sinister. He also reveals that the Yard apprehended a few of the top members of the gang. Frenchie LeBec (Tutte Lemkow) & Stevie Frey (Michael Ripper), recently broke prison. Addison Steele (Barry Foster) is still in custody. Clouseau decides to meet Steele inside prison and some intelligence about the gang's plans.
Sir Charles warns Clouseau not to trust anyone, even those in the Yard, as he is suspicious that there is a mole among their ranks. Meanwhile, Steele works as the prison's barber. When Clouseau arrives, Steele is cutting the hair of the warden's son, Clyde Hargreaves. Once Clyde is finished, Steele tells Clouseau that he does not know who the leader of the gang is, but only knows him by the name of "Johnny Rainbow." Clouseau is then tricked into a shave by Steele. During the hot towel treatment, Steele uses chloroform to subdue Clouseau and escape custody.
At Scotland Yard, Superintendent Weaver gives Clouseau experimental disguised weapons (like a laser, smoke signals, transmitter and recording devices, miniature missiles disguised in the belt buckle and so on) to help with his investigation.Superintendent Weaver (Frank Finlay) is the special equipment officer & Clouseau destroys his lab. Clouseau invites himself to dinner at Weaver's & meets Lisa Morell (Delia Boccardo), who is posing as a maid at Weaver's residence. Mrs Weaver (Beryl Reid) takes Clouseau to a Scottish festival, where he gets drunk.
Frenchie later attempts to assassinate Clouseau, who accidentally kills him with one of Weaver's weapons, the missiles in his belt buckle. Sir Charles is annoyed that Clouseau killed Frenchie, as they were unable to interrogate him. After realizing his own food has been poisoned, Clouseau finds a matchbook from a nearby inn called Tudor Arms on Frenchie's body.Clouseau is subsequently kidnapped on his way to Tudor Arms, when he is seduced by a female gang member Julie (Tracey Crisp). The gang members pour rubber on Clouseau's face, which they use to make a mold of his likeness.
Clouseau accidentally kills the owner of the inn by crushing him with a bed and realizes that he has a Johnny Rainbow tattoo. Charles is frustrated that Clouseau keeps getting leads and results in the case and believes it is blind luck. But Shockley believes that Clouseau's methods bring results.Clouseau goes to Frenchie's funeral in France as Weaver believes that the gang is bound to be attending the funeral as well, and Clouseau is a local who speaks the language. Clouseau is to look for more leads and is attacked by the gang. Weaver's maid, Lisa Morell, arrives and rescues him. She is actually an agent for Interpol who has been sent to help him. Clouseau does not believe Lisa's story and arrests her. However, his superior, Prefet De Police Geffrion, confirms she is telling the truth.
At the gang's hideout, Johnny Rainbow is revealed to be Clyde Hargreaves. Clyde Hargreaves (Clive Francis) is the son of the warden of the jail from which Stevie and later Steele had escaped. Turns out he is an active member of the gang & had helped them both escape. Clyde helps the gang use the Clouseau masks to plan a series of daring bank robberies across Switzerland. They plan to rob 13 banks in Switzerland simultaneously wearing Clouseau masks.
To make sure Clouseau is implicated the gang decides to kidnap him. Clouseau learns of the plan and goes to the hideout to investigate. Two of Rainbow's men, Bomber LeBec (Anthony Ainley) and Stockton follow Clouseau and attempt to kidnap him, but Weaver arrives and foils this. Weaver, who is actually the mole, slips a train ticket from Le Havre, France to Zurich, Switzerland in Clouseau's pocket and walks away.Weaver is revealed to be the member of the same gang. Weaver steals Clouseau's credentials & throws him off the train.
Weaver dons a Clouseau mask & is welcomed by the Swiss police in Zurich. Lisa warns him about Weaver, not realizing she is really speaking to Weaver in disguise. Lisa is kidnapped by the gang, and Rainbow puts on the disguise as Clouseau.
Clyde is Weaver's driver & on the way to the police HQ, Clyde dons a Clouseau mask and Weaver removes his. Together they instruct the Swiss police & the 13 bank presidents to transfer the funds into Clouseau's physical custody when he visits them by helicopter the next day. 13 banks are hit by gang members the next day precisely at noon, wearing Clouseau masks, who order the bank's president to transfer the cash into their custody, which they do.
The real Clouseau finally makes his way to Zurich, & his promptly arrested. The gang use a Lidnt chocolate factory to wrap the cash into Chocolate bars, which they load into a barge & agree to converge again in Cologne.
Weaver attempts to escape by disguising himself as Clouseau but is killed in a fight with the real Clouseau. This proves that Clouseau is innocent. He goes to rescue Lisa, chases after Steele and is eventually captured by Rainbow's men. Clouseau escapes using one of Weaver's weapons (a secret laser) and sinks the ship. The heist is foiled, but Rainbow and his men escape. Clouseau returns to France after saying goodbye to a grateful Sir Charles.