In the final days of World War II, Pietro 'Isola' Lamberti Pietro Castellitto is a shrewd contraband dealer trying to raise enough money to slip away from fascist-ruled Milan with his girlfriend, Yvonne Matilda De Angelis, a sultry singer who also serves as the mistress of the sadistic fascist minister Achille Borsalino Filippo Timi. Alongside his partners Marcello Davoli Tommaso Ragno and Amedeo Luigi Fedele, Isola intercepts a coded fascist order to evacuate a vast stash of looted treasures to Switzerland. The trio devises a daring plan to steal the treasure, concealed in a fortified quarter of Milan known as the Black Zone, and they recruit runner Hessa Coco Rebecca Edogamhe, anarchist Molotov Alberto Astorri, and former racecar driver Fabbri Maccio Capatonda, hoping to execute the heist within a week.
Isola is spotted leaving a date with Yvonne by Borsalino and his aide, Leonida Giorgio Antonini, and is warned to stay away from her. Yet Isola convinces Yvonne to steal Borsalino’s personal stamp to grant access to the Black Zone. While she is performing at her club, Yvonne collapses, prompting Isola to rush to the stage. He is captured by Borsalino and Leonida, triggering a shootout that ends with Isola and Yvonne escaping with Fabbri’s help. At Isola’s hideout, Yvonne reveals she is pregnant with his child. Nora Cavalieri Isabella Ferrari arrives and reveals she has been spying on Yvonne and Isola’s group all along, blackmailing Isola to hand over half of the fascist loot and staging the heist within 24 hours.
That night, Isola’s team slips into the Black Zone while Hessa orchestrates a false air raid and Molotov rigs the complex with explosives in the darkness. The plan falters when Isola, disguised as a prisoner, is halted by wary guards, triggering an early alarm. In the ensuing chaos, Molotov is mortally wounded yet manages to detonate the charges before he dies. The guards retreat to the bunker, allowing Isola and his remaining allies to seize the loot and flee in a truck. Meanwhile, Nora captures Yvonne and, alerted to the heist, bludgeons Borsalino to death.
Arriving at the rendezvous, Nora double-crosses Isola and demands the entire loot in exchange for Yvonne. After a tense Mexican standoff, Isola yields, but Nora reneges and drags Yvonne away. As Nora orders Leonida and his men to execute Isola’s group, a squad of partisans arrives and frees them after a gun battle, while Nora and Leonida escape in the truck with Yvonne and the loot. Fabbri finds a racecar nearby and joins Isola in a high-stakes chase to the Alps. Isola confronts Leonida in a separate vehicle, and Fabbri outflanks the truck, shooting the driver and sending the truck crashing into a lake. Isola and Yvonne emerge from the water, greeted by Fabbri’s relief as a radio broadcast announces the Axis surrender in Italy. In a mid-credits moment, Nora is shown to have survived and is hiding in a forest, leaving the fate of the remaining schemers unresolved.
