Tintin and the Lake of Sharks

Two criminals break into the Brussels aquarium at night and steal a priceless pearl. They replace it with a fake of the same size, exploiting the guards' distraction. The heist draws attention from the museum director and raises questions about security.

Security guards discover the missing pearl shell and report it to the director. The director is initially skeptical, thinking the guards are mistaken, but recalls a similar case at another museum two weeks earlier. This creates uncertainty and prompts a deeper investigation.

Tintin, Snowy, and Captain Haddock arrive in Syldavia to join Professor Calculus at his lakeside villa. At the airport they run into Thompson and Thomson, who are also heading to Calculus on a special mission. The encounter sets the stage for their shared adventure.

The group flies by hired plane to Calculus' villa, but engine trouble forces the pilot to bail out with the only parachute. Tintin attempts a safe landing, but the plane ends up on the edge of a cliff and catches fire. Two local children, Niko and Nushka, with their dog Gustav, rescue them.

Locals warn of a curse at the lake and a submerged town beneath it. The party reaches Calculus' villa, where he demonstrates a camera that can project holographic images and explains his dream of copying objects, though the copies are not yet stable.

During the night, Madame Flik is revealed to be in league with the criminals. The criminals attack with laughing gas and abduct the children while Tintin, Haddock, and Calculus are knocked unconscious. The home is taken by surprise as chaos erupts.

The criminals leave a message on a tape recorder from their leader, Rastapopoulos, who identifies himself as 'King Shark' and demands that Tintin perform an exchange for Calculus' invention. He warns not to involve the police. Tintin and Haddock start planning how to recover the children and stop the scheme.

Tintin discovers a hidden walkie-talkie in Madame Black's place, exposing the criminals' communications. He decides to contact the police and enlists Bianca Castafiore's help to reach them, hoping to avoid a diplomatic incident.

Two days later Tintin returns to Calculus' house with the shark-like submarine Calculus built, planning to meet the criminals on the beach while Haddock follows in his own sub. The arrangement is meant to secure the children and get Calculus' device back without directly triggering police action.

The criminals retreat to an underwater city base beneath the lake, where Rastapopoulos tests Calculus' machine by cloning a cigar box into a monstrous size. He locks Tintin and the children in a chamber, then orders a mass evacuation as the base begins to flood and self-destruct.

Haddock regains control of his submarine and reaches the surface, while Tintin and the children escape the base through an airlock just before it explodes. Police boats arrive and capture Rastapopoulos' men, but Rastapopoulos himself escapes in a submarine toward the border.

Tintin, Snowy and Haddock are welcomed back by Calculus, the Thompsons, Niko, Nushka, Gustav and villagers at Calculus' villa. Rastapopoulos is taken to Klow Prison, and Bianca Castafiore hosts a celebratory party; Haddock endures a prank when the Thompsons crash his whiskey bottle during a golf-themed moment.