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
The Doctor (Doctor Who) Caligari and subsequently responds to the question "Doctor who?" with "yes, quite right". Question marks adorning his costuming in the 1980s seem to imply the "Who" moniker. The only real exceptions are the computer WOTAN in the serial "The War Machines", which commands that "Doctor Who is required" and, towards the end of the Second Doctor serial "Fury from the Deep", the Doctor is addressed as "Doctor Who" by Mr Harris during the dinner party. The Third Doctor's car, dubbed "Bessie", carried the plate WHO 1, the only ongoing reference to the "Doctor Who" enigma in the original programme. The