Tintin, the Captain, and Snowy attempt to rescue Dr. Calculus who has been kidnapped by the Bordurians.

Tintin travels to the kingdom of Syldavia to stop a villainous gang from stealing the royal scepter and overthrowing the government.

Tintin and friends accept a ride to an astronautical congress in Australia in the plane of Laszlo Carreidas, but the plane is hijacked and the guests are landed on a Pacific island where an enemy uses a truth drug in an attempt to obtain the secret Swiss bank account number of their millionaire host.