A secret, high-technology international agency called SHADO defends Earth from alien invaders.

The International Rescue team is faced with one of its toughest challenges yet, as the revolutionary lighter-than-air craft Skyship One is hijacked while on her maiden voyage around the world. Against backdrops including the Statue of Liberty and the Sphinx, Lady Penelope, Parker, Alan and Tin-Tin fight the hijackers from on-board, while the rest of the team tries to stop the airship crashing.