Donna Noble, portrayed by Catherine Tate, was a secretary from Chiswick, London. She was a companion of the Tenth Doctor.
She appears in one scene at the end of the last episode of the 2006 series, “Doomsday” (named in the credits only as “The Bride”), and in the second Christmas special, “The Runaway Bride”. The character returned as The Doctor’s full-time companion for the whole of the fourth series in 2008.
During the 2006 series Christmas episode “The Runaway Bride”, Donna Noble is a temporary secretary at H.C. Clements in London, a security firm which, unknown to her, hide the Torchwood Institute up until its collapse following the events of “Doomsday”, and was then taken over by an alien intelligence. Her parents are Geoff and Sylvia Noble.
On Christmas Eve, the day of her wedding, she is accidentally pulled into the TARDIS because she has been drugged with Huon particles by her fiancé, Lance Bennett, because he was told to do so by Empress of the Racnoss. She aids the Doctor in defeating the Racnoss Empress, but says no to his invitation to travel with him — she is frightened not only by his adventures, but also by the Doctor himself. Having seen him commit genocide on the Racnoss, she urges him to find a new companion to act as his moral support. It was revealed later in “Turn Left” that the Doctor would have been killed while stopping the Racnoss if Donna was not there. Reappearing in April 2008’s Series four premiere, “Partners in Crime”, Donna has become dissatisfied with regular life and more interested in the bigger picture. She regrets declining the Doctor’s offer and has been investigating unusual phenomena in the hopes of finding the Doctor for some time. When investigating Miss Foster and Adipose Industries, the Londoner and the Time Lord are finally re-united. She expresses her regret to the Doctor for not joining him and after stopping Foster’s plans to convert the whole of London into Adipose children she joins him in the TARDIS as a regular companion. She makes it explicit, however, that she has no romantic attachment to him as Martha Jones and Rose Tyler did.