As the scorching August sun casts its rays upon the charming villa in Vence, French authorities unexpectedly arrive, intent on capturing the elusive American expatriate John Robie. With remarkable agility, he leaps over the garden wall, launching into a thrilling escape. Few know of Robie's infamous past as Le Chat ("the cat"), a bold and highly skilled burglar who left behind a stunning trail of jewel heists along the French Riviera in the late 1930s. His daring escapades earned him a fearsome reputation, marking him as one of the most elusive thieves of his era until his arrest in 1939.
During World War II, the German occupation of France prompted the release of numerous prisoners from French prisons, including Robie. Rather than succumbing to despair, he became a courageous member of the French Resistance (the Maquis), valiantly fighting against the Nazi regime alongside fellow prisoners. These shared tribulations forged bonds that would last forever.
In the war's aftermath, an unofficial amnesty was extended to those who had fought in the Resistance. Even though their past sentences lingered, they were offered a chance for renewal, provided they refrained from further criminal acts. While some ex-convicts returned to their nefarious ways, Robie chose a quieter life. He invested the fruits of his former crimes, bought his villa, and embraced a life of gardening and leisurely games of boules with the local townsfolk, including Commissaire Oriol and Count Paul.
Yet, serene days would not last long. A fresh surge of jewel thefts began to plague the Riviera, echoing Robie’s own history as Le Chat. As suspicions fell upon him once more, he reassured Oriol that the notorious alias belonged to a bygone era, silenced by the chaotic echoes of World War II. However, with every subsequent robbery, Oriol’s skepticism deepened, propelling him toward a relentless pursuit to capture Robie.
Following his daring getaway, Robie seeks out Bellini in Cannes, hoping to lay low and leave France behind. Nevertheless, Bellini entreats Robie to lend his expertise in capturing the new Le Chat — a figure employing methods that closely mirror Robie's own distinctive style. With the authorities tightening their grip on ex-convicts, the stakes could not be higher, and Robie faces a critical choice between maintaining his peaceful life or returning to the mantle of Le Chat to outsmart the new thief and exonerate himself.
Under the skilled hand of Jean-Pierre, Robie's true identity is cleverly disguised as Jack Burns, a portly, middle-aged American businessman on vacation. While navigating the vibrant nightlife and glamorous casinos of the Riviera, Robie, now as "Burns," identifies three likely targets for the elusive thief: the enigmatic Mrs. Stevens, the sophisticated Souzas, and the esteemed Sanfords. He meticulously crafts plans to infiltrate these potential targets, implementing his skills as Le Chat to facilitate precise burglaries.
However, unpredictability arises with Mrs. Stevens, who becomes infatuated with "Burns" while they share a moment at a casino, where she studies his betting and mirrors his moves. She dramatically wins two million francs, which she promptly uses to buy an extravagant diamond dog pin adorned with emerald eyes. As she lavishes attention on Lucky Burns, mimicking his betting style, she inadvertently draws unwarranted scrutiny.
Enter Bellini, who introduces the charming Danielle to Robie as a distraction, keeping Mrs. Stevens at bay. This arrangement annoys Claude, Danielle's muscular admirer, but serves to keep the captivating Mrs. Stevens blissfully unaware of "Burns'" true motives. Concurrently, Francie Stevens grows increasingly suspicious of any man who could take advantage of her unsuspecting mother.
When yet another heist occurs, Sûreté headquarters in Paris sends senior detective Lepic along with more agents to investigate. A tempting offer from Mr. Paige emerges: 20% of the jewels’ value for their safe return — no questions asked. Amid this frenzy, Robie encounters the oblivious Count Paul in Cannes, unaware of Robie's past as Le Chat.
As Francie becomes convinced Robie's gang is behind the thefts, she demands the return of her mother’s prized diamond dog, threatening to unveil the truth about Le Chat. Stalling for time, Robie navigates the situation while pondering who is truly behind the recent string of burglaries — his suspicions begin to swirl around Danielle and Claude, who might be implicated.
Diligently surveilling the Souzas' picturesque cottage, Coco and Robie remain alert for potential troublemakers. The following day, during a day at the beach, Robie provides a glimpse into their enigmatic world as he introduces Paul to Danielle, while narrating tales of heartbreak from his past.
Once again confronted by Francie for the diamond dog, Robie relents and shares his story — recounting his origins from his circus-performing parents to his childhood as an orphaned acrobat in Europe, detailing how circumstances transformed him into Le Chat.
Two nights later, while keeping watch at the Souzas' cottage, Robie spots a shadowy figure retreating under the cover of night. In a shocking turn of events, Detective Lepic fires, killing the Romani thief, seemingly validating Le Chat's innocence. Yet, Robie argues the real thief remains elusive, casting doubts over the investigation.
As the Sanfords prepare to host a lavish party, enticing guests adorned with exquisite jewels, Robie secures an invitation under his alias "Burns." Tensions rise; Count Paul demands that Le Chat vacate the premises, disregarding Robie's explanations while Lepic and Oriol arrive to safeguard the jewels.
As darkness approaches the chateau, Robie sheds his disguise and lies in wait for the elusive thief on the rooftop, his patience strained. When the thief finally strikes, Robie pursues her across rooftops, evading the authorities as Oriol urgently calls for Robie's surrender. In a breathtaking climax, Robie ultimately catches up to the thief, recognizing their shared instincts as they evade capture together.
As the night unfolds, feelings blossom—Paul expresses his affection for Danielle, suggesting a marriage proposal, offering to pay any price for her freedom. Yet, Robie proposes a plan: if Danielle delivers the stolen jewels to Paige, the gems would be returned, exonerating Le Chat.
With the stolen jewels restored and the criminal mystery resolved, Robie faces a poignant realization — his heart yearns for Francie Stevens, who is preparing to leave for America, marking the close of their romantic chapter. Upon returning to Vence, Robie finds Francie packing, definitive proof that some escapades are not meant to last, forever altering their destinies.
