1. some character(s) get into a life-threating situation somewhere in the world
2. International Rescue come to the rescue, aided by their hi-tech vehicles

International Rescue is a secretive organisation that resides on the fictional Tracy Island, run by Jeff Tracy and his sons, Scott, Virgil, Alan, Gordon and John, and Brains, the inventor of the rescue equipment. Each son is the operator of one of five vehicles, used in the rescue operations (pilot in brackets):

• Thunderbird 1 (Scott): rocket, first Thunderbird on the scene to assess the situation
• Thunderbird 2 (Virgil): equipment mover, used to get rescue equpment to the scene. Carries one of five pods containing specialised rescue equipment/vehicles to the scene
• Thunderbird 3 (Alan): spaceship, used to get to Thunderbird 5
• Thunderbird 4 (Gordon): submarine, used for aquatic rescue operations. Often carried in Pod of 4 Thunderbird 2 to the scene of the rescue
• Thunderbird 5 (John): space station orbiting earth, monitors radio frequencies for distress calls

Other characters include:

• Kyrano: Jeff Tracy's far-eastern manservant. He had devoted himself to Jeff's service becaue he had been saved by him years before. I believe Jeff was out there with the US Army, but I'm not sure.
• Tin-Tin: Kyrano's beautiful daughter. A major love interest of Alan, who was constantly being chastised for not keeping his mind on the job. My dad is convinced that Jeff had his eye on her too, but I think he was too nice a guy to do that.
• Lady Penelope: the London Agent. I have no idea what she actually did, but she was very rich, and very cool.
• Parker: Lady Penelope's butler. A ex-convict who was in one episode able to break into the Bank of England's main safe with a hair-pin.
• The Hood: the chief evil villain, who oppised International Rescue at every turn. His secret base was hidden in the heart of the jungle in Malaya, and he had nasty psychic powers. There was something distinctly snake-like about him (he was completely bald and had these glowing eyes - spooky!), and IIRC, he had a statue of a snake in his inner sanctum.

There were also some other vehicles:

• The Mole: A giant drill with an adamantium bit, that could drill through anything. Carried in one of the pods, which I believe could have been number six.
• Firefly: A bulldozer with immense levels of heat shielding that was used as a fire-fighter. It fired nitro-glycerine shells which would extinguish the fire by their percussive blast.
• Lady Penelope's car: a customised pink Rolls Royce. She a had a little telephone inside with which to talk to Parker, which was the height of fashion and technology in the '60s. The car also had big fat machine guns hidden in the front radiator, and an oil dispenser in the back bumper. It was all quite like Wacky Races.

Update, 27/5/01: I heard (from my Dad, oh the shame!) that there was also a Thunderbird 6. It featured in only one episode, however. It was a small biplane, and I have no idea what its function was, so I will add that when I find out.