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
Lost in Time (Doctor Who) on the DVD), "The Ice Warriors" (a condensed version, on the VHS release and as an extra on the DVD) and "The Web of Fear" (the still missing episode three, on iTunes and the DVD) – as well as being produced unofficially by fans. Lost in Time (Doctor Who) Doctor Who – Lost in Time is a BBC three-disc boxset DVD released in 2004. It is a collection of restored "Doctor Who" episodes and clips from stories that are incomplete or missing from the Corporation's archives. There were, at the time of release, 108 missing episodes, all from the black-and-white