The Doctor (Doctor Who) Time Lords a fixed number of twelve regenerations, meaning that every Time Lord had a total of thirteen incarnations including the original. The plot of "The Time of the Doctor" involves the Doctor receiving a new cycle of regenerations from the Time Lords before his expected demise, triggering the regeneration into the Twelfth Doctor, played by Peter Capaldi. The origins of the programme were explored in the docudrama "An Adventure in Space and Time" as part of the 50th anniversary celebrations of "Doctor Who", which starred David Bradley as William Hartnell. Although Time Lords resemble humans, their physiology differs in
David Bradley (English actor) "Band of Gold". In 1998, he appeared in the BBC adaptation of "Vanity Fair" as the miserly Sir Pitt Crawley, and "Our Mutual Friend" as the villainous Rogue Riderhood. Other television appearances include the 2001 series "The Way We Live Now", directed by David Yates, who would work with Bradley five years later on the "Harry Potter" films. From 2002–04, Bradley starred as Jake in the BBC comedy series "Wild West". Bradley acted in the 2004 musical drama serial "Blackpool" on BBC One. He appeared in the 2005 BBC drama "Mr. Harvey Lights a Candle", playing the role of a