Thunderbirds in trouble! International Rescue is forced to fight for its existence against the sinister Hood. Even the World Navy seems against the Tracys. It wants to use Tracy Island to test an atomic missile. It looks as if Jeff Tracy must either break security or see his organisation in ruins. But did the Hood triumph too soon? Brains has a plan. With the help of Lady Penelope and her Cockney chauffeur Parker, Scott Tracy and his brother can still save themselves and the world. All the incredible gadgets of the six-wheeled pink Rolls and of International Rescue's atomic Thunderbirds are used to the full in this exciting story of T.V.'s most amazing family.