Jonathan Frakes, the director of Thunderbirds, strolls up to me. "Red alert!" he shouts. He does this because we both know he's not really Jonathan Frakes: he's Commander Will Riker, born in 2335 in Valdez, Alaska, first officer of the Starship Enterprise in the TV series, Jean-Luc Picard's unstable sidekick, and lover of the irritating ship's counsellor, Deanna Troy. His main task was periodically to shout "Red alert!"

"You'll always be Riker to me," I reply, even though he looks a good deal more ragged and somewhat fatter than the great commander ever did. A shadow crosses his face, but then he grins.

"Loved you in Independence Day!" Riker/Frakes shouts to Bill Paxton, who plays Jeff Tracy, father of the Thunderbirds family. He says this because Paxton wasn't in Independence Day: he's deliberately confusing him with Bill Pullman.

"An old joke," murmurs Paxton apologetically.

"Loved you in Chicago Hope!" he cries to Anthony Edwards, who plays Brains. This is because he wasn't in Chicago Hope: he was the miserable, dying bald guy in ER.

Just as a touch of macho instability made Riker dominate the Enterprise's flight deck, so a distinctly manic air means that Frakes is the centre of attention on the Thunderbirds set. He is a bounding, Tiggerish vortex of activity. As if the jokes aren't enough, he also shouts "Action!" and "Cut!" very loudly indeed, and yells "Energy, energy!" at the actors as the cameras start to roll. And everybody on the set cries, "Print, print, hooray!" when he decides he likes a take.

"Energy is essential in these movies," he says.

The Thunderbirds set at Pinewood studios is, you will gather, one big private joke, a collective, self-referential nudge in the ribs and slap on the thigh. It is very, in a phrase, laid-back. It is made more so by the fact that the cast and crew agreed there would be no lunch breaks during filming. Instead they bring back polystyrene trays of food from the catering truck outside, sit among the cables and cameras, and eat while work continues.

When all this is combined with the vivid pastel colours of the set — the living room on Tracy Island — one feels that one has walked into the brilliantly lit dream of a benignly hyperactive child. But there is a serpent in this little paradise, a serpent of bitterness and resentment, of rejection and ingratitude. An original sin haunts this movie. For there is a man missing from this set, the one man, in fact, who should be here: Gerry Anderson, the creator of Thunderbirds.

"I simply wasn't asked to be involved," he tells me. "I don't legally have to be, because my pictures belong to Carlton Television, and I think they did a deal with Working Title [producers of the film]. Frankly, I think they were very stupid, because I think it's going to be very troublesome for them. Before I say another word, I should say I'm not big-headed, I promise you. But I have undoubtedly got a tremendous following. Every day of the week, people say to me in amazement, 'You're not involved with the film? I mean, it's ridiculous making a Thunderbirds film without you being involved.' Now I think that feeling is becoming very strong. It will embarrass them even if it doesn't affect the success of the picture."

On the set they don't want to talk about this. They mutter something about Anderson not liking Lady Penelope's car. But I will come back to the strange, sad and, for the film, ominous story of Anderson's exclusion.

The Thunderbirds set is disorienting, hypnotic and weird even by movie-making standards. But then the whole idea's weird. Here they are, making a film with real people based on a 1960s television series that used puppets whose arm movements (elbows bent, forearms projecting forwards, palms downwards, the whole assembly rising and falling to the command of an all-too-visible string) alone guaranteed a sort of cult immortality.

The original TV series was the creation of Anderson and his then wife, Sylvia, apparently on whom the character Lady Penelope was based. It ran for 32 episodes, ending in 1966. It should have run for many more, but Lew Grade, the boss of ATV, screwed up the negotiations for a sale to an American network, so it just sort of trickled out in the US. Nevertheless, two films were made — with puppets. Thunderbirds Are Go cost £250,000 and flopped in 1966. Thunderbird 6 cost £300,000 and flopped in 1968. The omens don't seem good.