Doctor Who: The First Doctor returns, setting up Christmas special

** Spoilers for 'The Doctor Falls’ ahead **

With the series ten finalé of Doctor Who having aired, there remains just one episode with Peter Capaldi and Steven Moffat behind the acclaimed BBC show.

To make the Christmas special truly spectacular, the show runner has brought back a legendary character, as teased during the last episode’s cliffhanger.

As Capaldi’s Doctor lay fatally wounded, attempting not to regenerate, another character approached, calling the plan “ridiculous”. That person was, astonishingly, the First Doctor, “The original, you might say”.

William Hartnell, who originally played the character, died in 1975, with David Bradley — best known for playing Walder Frey in Game of Thrones and Argus Filch in the Harry Potter films — portraying the Doctor. Bradley previously played Hartnell in the Doctor Who-focussed special William Hartnell, An Adventure through Space and Time.

This marks the first appearance of the First Doctor since 1983’s 'The Five Doctors', when he returned almost 20 years after originally regenerating.

The BBC has since confirmed Bradley is indeed playing the First Doctor, revealing that further casting announcements for the Christmas episode — which will feature a new Doctor — to be announced in the future. Meanwhile, Moffat has discussed whether Pearl Mackie will return to the series in the future.