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) of "cousins" and not produced via sexual reproduction. "Lungbarrow" portrays the Doctor as being one of 45 cousins grown from his house's genetic loom as an adult. By contrast, the TV programme has shown Time Lords as children, and stated that Time Lords can have sexual relationships. The Doctor is assumed to be or to have been married to Susan's grandmother, including by head writer Steven Moffat. In "The Wedding of River Song", he marries recurring companion and love interest River Song. Comments by both River and the Doctor in the seventh series, particularly in "The Angels Take Manhattan", confirmed