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
William Russell (actor) of the programme's fiftieth anniversary celebrations. Russell appeared as a character in the drama, portrayed by actor Jamie Glover. Russell also had a cameo role in "An Adventure in Space and Time" playing a BBC Commissionaire (security guard) named Harry. The same year, Russell portrayed both Ian and the First Doctor in the Big Finish audio play "The Light at the End", produced to celebrate the 50th anniversary of "Doctor Who". On 2 December 1988, Russell and his second wife, Etheline Margareth Lewis , had their first child Alfred Enoch, when he was 64 years old. Alfred is now an