Brains designed a new high-technology jet-assisted airship called Sky Ship One. However he will miss out on its maiden round-the-world flight when Jeff Tracy wants Brains to design a new Thunderbird vehicle.

Before the airship begins its round-the-world tour, a horde of assassins kill its crew and take over the airship so that they can lead the International Rescue team into trap, set by criminal identified as ‘Black Phantom’, by recording Lady Penelope and putting her words together to form a distress call.