Prologue (webcast)

 was the first prequel to the ninth series of Doctor Who, which was released 11 September 2015 on the Doctor Who website and BBC iPlayer.

It introduced the confession dial, a device pertaining to the Doctor's secretive past which would play an important role in the climactic events of Series 9, and saw the return of Ohila and the Sisterhood of Karn.

Plot
The Twelfth Doctor has returned to Karn, and discusses the nature of friends and enemies with Ohila, the leader of the Sisterhood. The two discuss an invitation given to the Doctor by an unnamed individual, someone who the Doctor has known for a long time, but has been enemies with for all that time.

Ohila doesn't believe the Doctor when he says he will not visit "him", and continues to question his reasons. Eventually the Doctor says he will go "soon", and gives Ohila a confession dial that he says she knows who to give it to. The Doctor comments that he should go meditate somewhere and then leaves the meeting spot.

Cast

 * The Doctor - Peter Capaldi
 * Ohila - Clare Higgins

Crew

 * Writer - Steven Moffat
 * Director - Hettie MacDonald
 * Producer - Peter Bennett
 * Executive Producer - Steven Moffat
 * Executive Producer - Brian Minchin

Story notes

 * This is the first prequel, mini-episode or webcast to feature the Twelfth Doctor.
 * This prologue is included in the shooting script for The Magician's Apprentice" that was released by the BBC Writersroom, indicating it was originally intended to be a part of the episode proper but was cut during the editing process. In the script, the scene takes place immediately after Sarff speaks to Ohila and departs, revealing the Doctor is present.
 * This is Ohila's first appearance that is contemporary with the show's ongoing narrative, rather than in the Doctor's past.
 * The Doctor's line to Ohila, "Look after the universe for me, I've put a lot of work into it." is identical to a line used in the 1999 Red Nose Day Comic Relief Doctor Who parody The Curse of Fatal Death, a spoof also written by Steven Moffat. The line in question was spoken coincidentally by that universe's version of the Twelfth Doctor as he was apparently dying for good. He asked his companion Emma, and the Master, to do the same. A variation of the line was also said by the Eleventh Doctor in The Eleventh Hour, though he was talking about Earth specifically.

Ratings

 * The video received over a hundred thousand views on YouTube within a week of release.

Filming locations

 * The whole story was filmed in the Taff's Well quarry in Cardiff, Wales.

Production errors
to be added

Continuity

 * The Doctor is present when Colony Sarff delivers the message to Ohila in TV: The Magician's Apprentice. As such, Prologue takes place entirely during the narrative of this episode.
 * The Doctor's fourth incarnation first met the Sisterhood of Karn and helped them when their flame was running out and Morbius was on the planet. (TV: The Brain of Morbius) Meanwhile, he had met Ohila in his eighth incarnation after the Sisterhood temporarily revived him from a fatal gunship crash. Ohila then gave him the means to regenerate into his war incarnation. (TV: The Night of the Doctor)
 * The person the Doctor is avoiding is later revealed to be Davros. (TV: The Magician's Apprentice)
 * The Confession Dial is later revealed to have been intended for . (TV: The Magician's Apprentice)
 * The Doctor said he would "probably go meditate on a rock". (TV: The Doctor's Meditation) He was previously meditating on top of the TARDIS. (TV: Listen)
 * The Doctor tells Ohila, "Look after the universe. I've put a lot of work into it." After recently regenerating into his eleventh incarnation, he made a similar statement to the Atraxi regarding Earth, responding to the Atraxi when they noted he was not native to that world with "No, but I've put a lot of work into it." (TV: The Eleventh Hour)
 * Ohila is aware of the Doctor's tendency to lie. (TV: The Big Bang, Let's Kill Hitler, The Wedding of River Song)

DVD releases
Included as a special feature on 'The Complete Ninth Series' Doctor Who box set.

Blu-ray releases
to be added