TOPKAPI

Jewel thief Elizabeth Lipp visits Istanbul, where she sees a traveling fair featuring replicas of treasures from the Topkapı Palace. She then cases the Topkapı, fascinated by the emerald-encrusted dagger of Sultan Mahmud I. Leaving Turkey for Paris, she recruits a former lover, Swiss criminal mastermind Walter Harper, to plan a theft of the dagger. At Walter's urging, they assemble a group of amateurs with no criminal history: Cedric Page, master of all things mechanical; Giulio, a mute acrobat known as the "Human Fly"; and the burly Hans Fischer, who will provide the muscle needed for the job.

In Kavala, Greece, Elizabeth and Walter hire small-time hustler Arthur Simon Simpson to drive a rented car across the border into Istanbul to transport hidden explosives and firearms for use in the heist. Simpson, unaware of Elizabeth and Walter's plans, is caught with the firearms at the border and detained by Turkish Customs officials on suspicion of plotting a terrorist attack at an upcoming military parade. Major Ali Tufan recruits Simpson to spy on Elizabeth and Walter for the Turkish police. Cedric, picking up the car in Istanbul, is told by a policeman that only the person who brought the car into the country is legally allowed to drive it. While traveling with the gang, Simpson surreptitiously drops messages hidden inside empty cigarette packs for his police handlers.

The gang's plan is to enter the Treasury of the Topkapı Palace from the roof through an upper window, with Hans lowering Giulio on a rope so the latter can steal the dagger and replace it with a replica without touching the floor, which has a built-in alarm system, while Walter uses a rope to lift the large glass case that encloses the dagger. However, Hans' hands are injured in a scuffle with the drunken cook, Gerven, and Simpson is enlisted as a substitute, prompting him to accidentally confess that he has been working undercover for the Turkish police. Knowing they face arrest if they try to escape Turkey or use their equipment, Walter improvises a new plan in which they will elude the still-oblivious police and steal the dagger without using their weapons. They will then "surrender" to the police, and claim to have found explosives in their car.

To establish an alibi as they are tailed by the police, the gang attends a crowded Turkish wrestling match, during which Walter, Simpson, and Giulio slip away to the Topkapı Palace. That evening, while Elizabeth and Cedric distract a lighthouse keeper and change the timing of the searchlight that illuminates the Treasury's wall, Walter, Simpson, and Giulio successfully steal the dagger. Unnoticed by the thieves, a bird flies in through the window during the heist and becomes trapped inside the room just before Giulio closes the window. The gang members deliver the dagger to Joseph, proprietor of the traveling fair display, who will smuggle it out of Turkey.

The gang goes to police headquarters to "reveal" their discovery of weapons in the car. The inspector asks Simpson to vouch for Elizabeth and Walter's whereabouts that day. Simpson, seeming to waver, confirms their alibi. Before the police release Simpson and the others, the trapped bird in the Topkapı triggers the alarm, alerting police officers across Istanbul. When word of the Topkapı alarm reaches the police, Major Tufan confronts the thieves, displaying Simpson's last message, which has just enough information to link all of them to the heist. Tufan informs the gang that he knows why they were in Turkey: "A little bird told me", he says.

Ultimately, the gang is sent to a Turkish prison, where Elizabeth devises a new scheme to steal the Russian Imperial Crown Jewels in the Kremlin. Some time later, the gang, having seemingly escaped from jail, walks in the snow in a Russian city.

The gang successfully steals the emerald-encrusted dagger from the Topkapı Palace but ultimately ends up in police custody after their plan is unraveled.

Topkapi’s climax cleverly subverts the classic heist by letting its mismatched crew savor their unlikely success momentarily, only for unforeseen complications (including an unnoticed bird setting off the museum alarm) to seal their fate. The ending underscores the unpredictability of even the best-laid plans and injects a wry sense of humor into the genre’s conventions by blending triumph with comedic defeat.