Keep Circulating the Tapes: The series pilot was never broadcast. Featuring a live audience, it overran in studio - and also contained a game involving the electrical conductivity of salt water, something it was felt was highly inappropriate for a series which children would be watching.
Missing Episode: The series was one of the victims of the BBC children's TV purge of 1993, with four episodes (out of 22) lost from the archives, two each from Series 1 and 2. Episode 5 of Series 1 and Episode 2 of Series 2 circulate on the trading circuit and were included in the 2017 DVD release, while Episode 2 of Series 1 (Stephen Cox, Liza Goddard, Michael Rodd) is believed to exist in a private collection whose owner is unwilling to return the tape. Episode 4 of Series 2 (Derek Griffiths, Tessa Hamp, Nerys Hughes) was not known to exist in any collections until a copy was uploaded to YouTube in 2020.
Serendipity Writes the Plot: The episodes lasted about 40-45 minutes but were condensed from two-hour recordings, so that viewers could watch the more active puzzle solving instead of contestants standing around muttering "What do we do next?" or thinking in near silence. However, the episodes of Series 1 had irregular times for recording sessions (so that two episodes lasted under 30 minutes, two lasted about 37 minutes, and only one lasted the "full" 45 minutes), which sometimes affected how the episode played out. For example, in Episode 4 (Denise Coffey, Toby Freeman, Garry Hunt), the production crew had so little time to record the episode that the contestants were given a free pass home instead of being made to backtrack across the now electrified tiles they crossed at the beginning, while in Episode 5 (Paul Darrow, Lesley Judd, Robert Malos), the Argonds had to resort to giving more and more obvious clues for the puzzles as studio time ran desperately short, and the electrified grid was effectively turned off except for one trapped tile.
The idea of children being able to phone in helpful suggestions was briefly considered, before it was realized that this would mean transmitting the show live. The concept resurfaced in the third season with pre-filmed viewer inserts.
Of the 66 contestants across the series, just 24 were able to go home by spaceship, while the other 42 were evaporated and had to walk home.
In Series 1, the lucky ones were the Episode 1 team of Mark Dugdale, Elizabeth Estensen, and Fred Harris, and the Episode 4 team of Denise Coffey, Toby Freeman, and Dr. Garry Hunt (the latter didn't even have to cross an electrified grid due to lack of studio time).
When the Vortex was introduced in Series 2, the only two contestants to successfully cross the grid were Philip Sheppard and David Singmaster, both in Episode 3, but the four falsely accused Moles - Graeme Garden, Derek Gale, Derek Griffiths, and Bill Green - were given a free pass across the grid and still got to take the shuttle home.
Series 3 saw victorious crossings from Sarah Greene and Anne Miller in Episode 1, Nigel Crocket in Episode 5, and Ray Virr in Episode 6. Three contestants - Chris Serle from Episode 3, Christopher Hughes from Episode 4, and Neil Adams from Episode 5 - didn't even get as far as the Vortex grid, with the Rangdo evaporating them for offering him substandard gifts.
Series 4 featured the most successful crossings, from Sheelagh Gilbey and Ian McNaught-Davis in Episode 1, Ian McCaskill in Episode 3, Prof. Heinz Wolff and Ruth Madoc in Episode 4, and the entire team of George Layton, Joanna Monro, and Val Prince in Episode 5.
