The Sicilian Clan

In Paris, robber and murderer Roger Sartet escapes from custody with help from the tight-knit Sicilian clan the Manalese. The clan accepts Sartet in exchange for valuable stamps, and they hide him in an apartment above their front business, a game-arcade and manufacturing company. The escape marks the beginning of the coordinated heist plan.

Jeanne, Vittorio's elder son's French wife, tends to Sartet as he hides with the Manalese. He still sneaks out to meet a prostitute at a hotel and narrowly avoids capture by Commissaire Le Goff.

Sartet, while in prison earlier, learned about the security for the jewelry exhibition in Rome. He proposes the Manalese help him rob the show, but the clan is skeptical of the hot-headed outsider and sends Vittorio with Tony Nicosia to assess the security themselves.

Tony Nicosia devises a plan to steal the jewels in transit after realizing security changes. He sends Jack, an alcoholic ex-pilot, to Paris to help the Manalese with the heist, launching the external support network.

Commissaire Le Goff tracks down the forger who made Sartet's fake passport. Coincidentally, Vittorio is using the same forger to supply multiple fake documents for the operation. Le Goff questions Vittorio but is told the employee no longer works for him.

The Manalese retreat to a hideout near the Italian border to coordinate the operation and keep Sartet under protection. The group tightens its plans as they prepare for the Rome exhibition heist and the transport of jewels.

Sartet travels to Rome and discreetly abducts Edward Evans, an English insurance man, then takes Evans's place among the small group of officials guarding the jewels during their trip. The swap allows Sartet to slip into the guard role and create the path to the heist.

Mrs. Evans unexpectedly joins the group and plans to accompany her husband to New York. During the plane's loading, she calls the hotel in Rome to confirm Evans's whereabouts and identifies Sartet among the guards, triggering police attention.

During descent toward New York, the Manalese hijack the aircraft. Police race to the airport, but Jack lands the plane on a new stretch of highway not yet open, allowing the gang to split and flee with the jewels.

Sartet hides out in New York while waiting for his share and a ticket to Veracruz. Back in Paris, Vittorio withholds Sartet's loot and initiates a plan to lure him back, while Jeanne's relationship complicates the ruse.

Monique, Sartet's sister, travels to the airport after Jeanne asks her to warn Sartet. Le Goff raids the waiting group when he arrests Vittorio's sons and son-in-law, catching them as they waited for Sartet.

Sartet, having arrived in Paris ahead of schedule, agrees to meet Vittorio at an isolated spot to count the money. Vittorio brings Jeanne, and, while Sartet examines the loot, Vittorio shoots both Sartet and Jeanne, leaving the cash by the corpses. Le Goff appears soon after to arrest Vittorio.