On a rainy winter day in Saint-Jean-de-Monts, France, Simon and his three accomplices rob a bank. Marc Albouis and Paul Weber come inside with Simon, while Louis Costa, the getaway driver, waits outside. As they are about to leave, the teller sets off the alarm and shoots Marc, who shoots and kills the teller. The gang escape with only part of the loot and drive back to Paris, where they place Marc in a private clinic under the alias "Schmidt".
Commissaire Edouard Coleman spends his nights driving around Paris from crime scene to crime scene. He also meets with his informants, such as Gaby, a transgender prostitute who is currently feeding him information about an upcoming drug shipment that involves one of her clients. Edouard goes to the nightclub Simon owns just after it closes for the night and plays the piano while Simon's girlfriend, Cathy, watches. Simon returns from Saint-Jean-de-Monts, and Edouard greets him before getting called away by his partner, Inspector Morand.
As the press reports that one of the assailants was injured during the robbery, Simon, Louis and Paul set out to transfer Marc out of the clinic before the police search the facility. When a nurse refuses to release Marc due to his health status, Simon sends Cathy into his room disguised as a nurse, and she injects air into his IV, causing a fatal embolism. Edouard is assigned to investigate the true identity of "Schmidt", but he does not expect to succeed. He meets Cathy in a hotel room for a tryst, and later deduces that Simon has always known about their affair.
Simon's next venture is to steal a large quantity of heroin being transported out of France by a professional mule, Mathieu "la Valise", on a night train from Paris to Lisbon, with Mathieu's associates delivering the drugs to him in Bordeaux. Tipped off by Gaby, Edouard sets up an operation to catch Mathieu in Bayonne. Meanwhile, Simon descends from a helicopter onto the speeding train, breaks into Mathieu's cabin, neutralises him with chloroform, and is successfully winched up with the drugs.
Furious that the drugs were not recovered, Edouard berates Gaby and slaps her around for supposedly providing him with false information. When Morand presents Edouard with Marc's autopsy, revealing his real name, Edouard instantly connects Marc to Louis, who is a known associate of Simon. He calls Simon, who is not available, and then calls his chief to ask if Marc's name can be kept out of the press, but the chief says it is too late.
Edouard arrests Louis at a restaurant and brings him to the precinct, where Edouard gets the seemingly indomitable Louis to name Simon and Paul. Edouard goes to the nightclub alone and questions Simon, who denies knowing Marc, Paul or Louis. Edouard then reveals that Louis admitted to knowing Simon, before leaving. Simon immediately warns Paul by telephone, but Edouard and some of his men arrive and burst into Paul's apartment before he can flee; Paul ultimately shoots himself in the head.
Simon hides out in a hotel and calls Cathy to pick him up, but the police trace the call. As Simon emerges from the hotel carrying an attaché case full of heroin, the waiting Edouard draws a gun and tells him not to move. Simon reaches into his overcoat, and Edouard shoots him dead while Cathy watches helplessly from her car. However, when Edouard inspects Simon's body, he finds he had no gun, leading him to believe it was suicide by cop. Edouard and Cathy exchange glances before he and Morand are called away on another case. Their car phone rings, but they do not answer.
Jean-Pierre Posier as one of the men who hands over the heroin to Mathieu in Bordeaux
Jacques Leroy as one of the men who hands over the heroin to Mathieu in Bordeaux
Michel Fretault as an employee at the branch of BNP in Saint-Jean-de-Monts
Gene Moyle as the elderly man on the train
Pierre Vaudier as the manager of the branch of BNP in Saint-Jean-de-Monts
The film's crew included Alain Delon's brother, Jean-François Delon (first assistant director); Jean Gabin's daughter, Florence Moncorgé (script supervisor); and Jacques Tati's son, Pierre Tati (second assistant director), and daughter, Sophie Tati (assistant editor).
References
^"Un flic (1972)". JP Box-Office (in French). Retrieved 14 February 2014.
