mission by technologically-advanced land, sea, air and space vehicles that are called into service when conventional rescue methods prove ineffective. The most important of these vehicles are the five "Thunderbird machines", each assigned to one of the five Tracy brothers: Thunderbird 1: a blue and silver hypersonic rocket plane used for fast response and danger zone reconnaissance. Piloted by Scott, rescue co-ordinator. Thunderbird 2: a green supersonic carrier aircraft that transports supporting rescue vehicles and equipment in detachable capsules called "pods". Piloted by Virgil. Thunderbird 3: a red single-stage-to-orbit spacecraft. Piloted alternately by Alan and John, with Scott as co-pilot. Thunderbird 4: a utility yellow submersible. Piloted by Gordon and usually launched from Thunderbird 2. Thunderbird 5: a grey and gold space station that relays distress calls from around the world. Manned alternately by "space monitors" John and Alan. The family live on Tracy Island, International Rescue's base of operations in the South Pacific Ocean, in a luxurious villa that they share with four others: Jeff's mother, Grandma Tracy; the bespectacled scientist and engineer Brains, who designed the Thunderbirds machines; Brains' assistant Tin-Tin, who is also Alan's girlfriend; and Tin-Tin's father Kyrano, the Tracys' retainer. In this remote location, International Rescue is safe from criminals and spies who envy its technology and aim to acquire the secrets of the Thunderbird machines. Some of International Rescue's operations are triggered by sabotage or negligence instead of accidents. For missions requiring espionage, the organisation incorporates a network of undercover agents headed by English aristocrat Lady Penelope Creighton-Ward and her butler Aloysius Parker. Based at Creighton-Ward Mansion in Kent, Penelope and Parker travel in FAB 1, a specially-modified Rolls-Royce. Members of International Rescue acknowledge orders with the expression "FAB" (a shortening of the 1960s vogue word "fabulous", but spoken like an initialism: "F-A-B"). International Rescue's most persistent opponent is master criminal the Hood. Based in a temple in the Malaysian jungle and possessing powers of hypnosis and dark magic, the Hood exerts a telepathic control over Kyrano, his estranged half-brother, and manipulates the Tracys into rescues that unfold according to his own malevolent designs. This gives him opportunities to spy on the Thunderbird machines and, by selling their secrets, make himself rich. Production Thunderbirds was the fourth Supermarionation puppet TV series to be produced by APF, which was founded by the husband-and-wife duo of Gerry and Sylvia Anderson (née Thamm) with their business partners