With the tenth series of Doctor Who now over, attention has turned towards the upcoming Christmas special — AKA Peter Capaldi and Steven Moffat’s final episode before Chris Chibnall takes over with an as-yet unannounced new Doctor.

Moments after 'The Doctor Falls’ broadcast, the BBC released the official synopses for the Christmas special, confirming Game of Thrones' David Bradley’s version of The First Doctor — glimpsed moments before the series ended — will play an integral role in the multi-Doctor adventure.

“The cliff-hanger ending saw the Doctor fatally injured and beginning to regenerate,” reads the synopses. “Stepping out of the TARDIS into an arctic landscape, he fought off the glowing regeneration energy and fell to his knees, vowing that this time he would not live on and change into a new Doctor.

“This was declared ‘ridiculous’ by an approaching figure, who mocked the Doctor as he stepped forward through the snow to reveal himself as the very first incarnation of the Time Lord (“The original, you might say”) just before the credits rolled. The story will continue at Christmas.”

Stars in Doctor Who and Game of Thrones Show all 10 1 /10 Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Maisie Williams – (left: She'll make a special appearance in Doctor Who, right: Game of Thrones – Arya) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Tobias Menzies (left: Doctor Who – Lieutenant Stepashin, Cold War, right: Game of Thrones – Edmure Tully) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones David Bradley: (left: Doctor Who – William Hartnell, An Adventure through Space and Time; GoT – Walder Frey) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Liam Cunningham (left: Doctor Who – Captain Zhukov, right: Cold War & Got – Davos Seaworth) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Joe Dempsie – (left: Doctor Who - Cline, The Doctor’s Daughter; right: Game of Thrones – Gendry) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Thomas Brodie-Sangster (left: Doctor Who - Tim Latimer, Human Nature/The Family of Blood; right: Ggame of Thrones - Jojen Reed) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Iain Glen (left: Doctor Who – Octavian, Flesh and Stone/The Time of Angels; right: Game of Thrones - Ser Jorah Mormont) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Julian Glover (Doctor Who - Count Scarlioni/Scaroth, City of Death; Game of Thrones - Grand Maester Pycelle BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Dame Diana Rigg (Doctor Who - Mrs. Gillyflower, The Crimson Horror; Game of Thrones - Olenna Tyrell/Queen of Thorns) BBC/HBO Stars in Doctor Who and Game of Thrones Stars in Doctor Who and Game of Thrones Harry Lloyd (Doctor Who – Baines, Human Nature/The Family of Blood; Game of Thrones Viserys Targareyenn) BBC/HBO

The upcoming special will mark the first time the Doctor has appeared actively onscreen since 1983’s 'The Five Doctors', when the character returned to the series following his regeneration almost 20 years prior.

Further casting details will be announced in the near future, with the likely revelation over who will take the coveted role as the next Doctor Who.

Two official photographs have also been released, one starring Capaldi in sunglasses with Bradley’s Doctor behind, the other featuring the snowy landscape seen in the final moments.

Speaking on the after-show, Moffat said of filming the Christmas special — which will be directed by long-time collaborator Rachel Talalay: "At this moment we’re filming the Twelfth Doctor and the First Doctor meeting.

"Right now, I’ve just been on the set of the First Doctor’s TARDIS which has been beautifully recreated. David Bradley’s recreation of William Hartnell is so eerily perfect, it could fool you. I’ve just been watching a scene where he is so perfectly William Hartnell, you could be convinced it’s him.”