Prologue (webcast)

 was the first prequel to the ninth series of Doctor Who, which was released on 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 from The Night of the Doctor, and their first appearance in a post-Time War setting.

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 Producers - Steven Moffat, Brian Minchin

Story notes

 * This is the first prequel, mini-episode and 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 Colony Sarff speaks to Ohila and departs.
 * The placement of this minisode becomes apparent during the episode itself.
 * 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 dying. He asked his companion Emma, and the Master, to do the same.

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'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) 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" after leaving Karn. (TV: The Doctor's Meditation)
 * 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