The Doctor (Doctor Who) footage. Tom Baker did reappear, but as "the Curator", an ambiguously different character who he was not credited for playing. A voice actor, John Guilor, recorded a line of audio impersonating the First Doctor, for which he was credited as "Voice Over Artist". In other multi-Doctor stories, the multiple actors are all credited as "The Doctor", the exception being "The Three Doctors" (1972–73), which credited William Hartnell, Patrick Troughton and Jon Pertwee as "Doctor Who" as the 1972 serial preceded the practice of crediting the character as "The Doctor". In "Human Nature" (2007), the plot involves the Tenth Doctor altering
Doctor Who and the Daleks in the Seven Keys to Doomsday early 1970s, and was a fan of "Doctor Who". In 2008 Big Finish Productions released "The Seven Keys to Doomsday" as an audio drama, directed by John Ainsworth. Doctor Who and the Daleks in the Seven Keys to Doomsday Doctor Who and the Daleks in the Seven Keys to Doomsday was a stage play based on the long-running British science fiction television series "Doctor Who". The play ran at the Adelphi Theatre in London, England for four weeks, beginning on 16 December 1974. Originally, the part of the Doctor was to be played by Jon Pertwee, but the role went