In the Istanbul museum of Topkapi there happens to be a priceless ceremonial dagger that a certain criminal mastermind called Elizabeth Lipp (Melina Mercouri) has her eye on. She contacts an old flame, expert thief Walter Harper (Maximilian Schell), and informs him of her plans to set up a heist on the museum and he willingly goes along with them, as long as he sets the parameters. His main idea is to assemble a gang not of professionals, but of amateurs, and one with no criminal records as well. This means the authorities will not be suspicious, but there's one chap they hire, Arthur Simpson (Peter Ustinov), a cheap and unsuccessful conman, who just might bring down their operation if they're not careful - but you wouldn't believe how careful they can be.
Director Jules Dassin won international praise for his previous heist movie Rififi, whose famous setpiece was a cleverly planned robbery, so why not repeat the trick a decade later with Topkapi? It was adapted by Monja Danischewsky from Eric Ambler's novel "The Light of Day", and its own heist sequence, which fills up the second hour of the movie, was justly recognised as a small masterpiece of direction, on the part of the criminals as well as Dassin. He cast his wife in a role that didn't really need to be there, and Mercouri introduces the film in a bizarre opening sequence verging on the psychedelic that is oddly unnerving, mainly due to Mercouri. With her piercing eyes and shark-like grin, along with a intense cheeriness, she's not the most relaxing of presences and threatens to derail the supposed fun of the following caper.
Fortunately, she doesn't really make up an important part of the film, and is barely seen in the second half where the plan comes together, but nonetheless - brr. Anyway, Elizabeth and Walter make their way to Greece to pick up Arthur, who is peddling his wares by the beach and failing miserably to make a sale. However, it's his lucky day and he is asked to drive a car into Turkey for the couple, an offer he accepts for the money it will award him, but not all goes smoothly. At the border customs, Arthur is stopped and the guards find a stash of weapons hidden in one of the doors, something he cannot persuade them he knew nothing about, and the Turkish police begin to suspect there might be gun running going on and hire Arthur as a spy to check up on the gang (he has to send the authorities coded messages).
But is this all part of the plan? Walter seems to have thought of everything, and once everything is in place he sets the wheels of the heist in motion, drawbacks like the hired strongman breaking his fingers taken care of by replacing him with the portly Arthur. Ustinov is in danger of running away with the picture, if it wasn't for Robert Morley as a fellow crook (and gadget wizard) he probably would, and won an Oscar for his trouble. There's a pleasant breeziness to the handling, and though the first half is stodgy you can see where the setting up pays off when it all falls into line. The crime itself involves swapping the dagger, which is kept under glass on a floor that has an alarm system sound should anyone step on it, for a fake (I thought the twist would be that they got the wrong one when the acrobatic human fly nearly drops them both), and is carried out with the minimum of noise to focus the mind and crank up the tension. Topkapi is nicely done, but it's a little too pleased with itself and the final twist too contrived. Music by Manos Hadjidakis.