Learning from the weaknesses of the Thunderbirds Are Go feature film which premiered to a much smaller audience than originally expected in December 1966, Thunderbird 6 went into production in May 1967 alongside the production of Captain Scarlet which had started in January. The Century 21 studio divided once again with one team tackling Thunderbird 6 while the other continued to produce episodes of Captain Scarlet. This lasted for 4 months. The film was completed and classified by January 1968, but was then shelved for 6 months for release in July. More than 18 months had passed since a new episode of Thunderbirds had been broadcast, and when Thunderbird 6 went into production it had been at least 6 months since the team had worked on any major Thunderbirds productions. How did such a long break affect the finished product and its reception? There’s no doubt that Thunderbird 6 addresses some of the weaknesses of Thunderbirds Are Go, but does it present other problems? Ultimately, this is the final adventure for the International Rescue team produced in the 60’s by the original Century 21 team – so was this film one last hurrah, the glimmer of a new direction for the format, or the reason it all came to an end?