Twice Upon a Time (TV story)

 was the 2017 Doctor Who Christmas special. The special is the final episode to be written under showrunner Steven Moffat's tenure in the series and features Peter Capaldi in his last appearance as the Twelfth Doctor. The special also sees the return of Bill Potts and Nardole, though not the real versions of the Doctor's companions, as well as a surprise appearance from Jenna Coleman as Clara Oswald, with the Doctor's memories of her being restored after the events of Hell Bent (TV story). The story features regular writer Mark Gatiss in the role of a character only known before the episode's release as 'The Captain', before the end of the episode revealed him to actually be Archibald Hamish Lethbridge-Stewart.

This Christmas special is notable for numerous reasons for series; it marked the first full appearance of the First Doctor outside of archive footage and stand ins since The Five Doctors, as well as his first full adventure since that anniversary special, and as with The Five Doctors the First Doctor is played by a different actor, this time David Bradley, who had a surprise appearance as the Doctor in the finale for Series 10 The Doctor Falls and had played original Doctor William Hartnell in An Adventure in Space and Time, though Hartnell himself does appear as the Doctor through the use of archive footage to help tie in the First Doctor's role in this story. The story also shows the brief return of Ben Jackson and Polly Wright, though much like the First Doctor played by different actors. This is also the full episode of the BBC Wales series to show two different incarnations of the Doctor from two different eras of the series' history, with the First Doctor representing the classic era while the Twelfth Doctor obviously representing the BBC Wales era of the series, though while Time Crash had been the first story to show two different incarnations of the Doctor from both the classic and BBC Wales series meeting Twice Upon a Time would be the first full story to feature this happening.

For the original incarnation of the Doctor the episode shows his first encounters with many of the things that have now became a staple of the series, such as his first encounter with any of his future incarnations, as well as different interiors for the TARDIS, and most notably his first look at the Sonic Screwdriver, revealing that the First Doctor had never used it before until after he regenerated. This would also be the Doctor's first encounter with the Lethbridge-Stewarts through Captain Archibald Hamish Lethbridge-Stewart, whose members of the family the Doctor would soon meet later on in his life.

The Christmas special is very notable for retconning one major event in the Doctor's life, in that the episode shows the First Doctor had one last adventure during the events of The Tenth Planet before he regenerated, and continuing from the Twelfth Doctor's refusal to regenerate from the last episode, here it's revealed that the First Doctor was scared of changing into a different person and had actually tried doing the same thing as his future successor, and for most of the story until the end both Doctors were prolonging their regenerations, the longest time any incarnation of the Doctor has prolonged a regeneration before, however the First Doctor soon accepts his impending change after seeing the good he's going to do in his life and his story ends with his regeneration into the Second Doctor, marking the first time two incarnations of the Doctor are seen regenerating in the same story and also helps explain why the TARDIS console had begun moving on it's own during the First Doctor's final moments.

The most notable moment of the entire episode however was the introduction of Jodie Whittaker as the Thirteenth Doctor. Whittaker is the first actress to take on the role and portray the previously male Doctor in the history of the series run, as well as marking the introduction of the first ever incarnation of the Doctor to be female rather than male.

Synopsis
Two Doctors stranded in a foreboding snowscape, refusing to face regeneration. In the final chapter of the Twelfth Doctor's adventure, he must face his past to decide his future. It is the end of an era, but the Doctor's journey is only just beginning...

Plot
to be added

Cast

 * The Doctor - Peter Capaldi
 * The Doctor - David Bradley
 * Bill - Pearl Mackie
 * The Captain - Mark Gatiss
 * Clara - Jenna Coleman
 * Nardole - Matt Lucas
 * The Glass Woman - Nikki Amuka-Bird
 * German Soldier - Toby Whithouse
 * Polly - Lily Travers
 * Ben - Jared Garfield
 * Voice of the Daleks - Nicholas Briggs
 * And introducing Jodie Whittaker as the Doctor

The Tenth Planet

 * The Doctor - William Hartnell (archival)
 * Polly - Anneke Wills (archival)
 * Ben - Michael Craze (archival)

Crew
to be added

Story notes
to be added

Ratings
to be added

Filming locations
to be added

Production errors
to be added

Continuity

 * The Doctor recalls Bill's cyber-conversion and apparent death. (TV: World Enough and Time / The Doctor Falls)
 * Bill reminds the Doctor about Heather and the sentient oil. (TV: The Pilot)
 * The Doctors promise to check up on the family of Lethbridge-Stewart. (TV: The Web of Fear et al.)
 * The Doctor was present for the Christmas truce of 1914 earlier in his first incarnation (PROSE: The Little Drummer Boy) as well as during his fifth (PROSE: Never Seen Cairo) and ninth incarnations. (COMIC: The Forgotten)
 * The Doctor once more explains why he ran away from Gallifrey. (TV: Heaven Sent)
 * The Doctor meets Rusty again. (TV: Into the Dalek)
 * The Doctor refers to the year 5 billion and New Earth. (TV: New Earth, Gridlock)
 * The Doctor holds a Dalek Eyestalk. (TV: The Wedding of River Song, The Time of the Doctor)
 * The Doctor is referred to as "the Doctor of War". (TV: A Good Man Goes to War, The Name of the Doctor, The Day of the Doctor)
 * The Doctor encounters his first incarnation. He has experienced such before, (TV: The Three Doctors, The Five Doctors, The Day of the Doctor) and also struggles to remember the encounter. (TV: Time Crash)
 * The Doctor once more pilots his predecessors TARDIS. (TV: The Day of the Doctor)
 * The Doctors banter about their differences. (TV: Time Crash, The Day of the Doctor)
 * The Twelfth Doctor favorably remarks about the First Doctors desktop theme in his TARDIS. The Tenth and Eleventh Doctors did similar regarding the War Doctor's TARDIS. Likewise, The First Doctor criticizes the Twelfth Doctor's desktop theme just as the Tenth did to Eleven's. (TV: The Day of the Doctor)
 * The events of The Tenth Planet are referred to.
 * The Testimony shows the Doctors the amount of times they have become associated with wars. Notably, events from The Waters of Mars, Journey's End, The Day of the Doctor, The Name of the Doctor.
 * The Eleventh Doctor's conflict at Trenzalore is mentioned by the Testimony, (TV: The Time of the Doctor) as is the Time war. (TV: Dalek et. al)
 * The Doctor mentions the Dalek's Pathweb. (TV: Asylum of the Daleks, The Time of the Doctor)
 * The Doctor once more references River Song's words from her diary. (TV: Extremis, The Doctor Falls)

DVD releases
to be added

Blu-ray releases
to be added

Digital releases
to be added