All six episodes of this serial were erased from the BBC archive in the late 1960s and the 16mm prints made for foreign markets were destroyed in 1974. Luckily fans at the time recorded the soundtrack directly from the television, this has been paired with newly created animation in an attempt to reconstruct the missing episodes from this serial.
Working titles for this story included The Destiny of Doctor Who and Servants of Masters. Anneke Wills was on holiday and therefore absent from episode four. Similarly, Michael Craze was absent for episode five.
In the first episode, a small scene in which the Doctor is playing his recorder while dancing was cut. This was a practical decision, as animating his fingers and his dancing was very complex and the result unsatisfactory. The deleted scene was later added in the 2020 Special Edition.
In early August 2016 two minutes of animated footage from this project were leaked on to YouTube, the BBC removed it within 24 hours.
Charles Norton, director/producer of the animated version, was not credited on the color version of the film.