Doctor: Jodie Whittaker
Alan Cumming – King James
Siobhan Finneran – Becka Savage
Tilly Steele – Willa Twiston
Tricia Kelly – Old Mother Twiston
Arthur Kay – Smithy
Stavros Demetraki – Alfonso
Directed by Sallie Aprahamian
Written by Joy Wilkinson
Script editor: Fiona McAllister
Produced by Alex Mercer
Executive producer(s) Chris Chibnall, Matt Strevens, Sam Hoyle
Incidental music composer: Segun Akinola
Length 50 minutes
First broadcast 25 November 2018
The Doctor and her companions end up in 1612 Lancashire near Pendle Hill. They reach a nearby village to find an old woman accused of witchcraft being dunked, and the Doctor tries to save her but fails. She attempts to prevent further trials by claiming herself as a Witchfinder General to the local landlord Becka Savage, only for the sudden appearance of King James I to complicate matters as he deems her as Graham's assistant. Meanwhile, Yasmin finds the old woman being buried by her granddaughter Willa Twiston and saves her from a tendril made of mud. Upon hearing of this, and that Savage is Willa's cousin, the Doctor realizes the cause of the witch hunt is of alien origin as the recent victims are being reanimated by the alien entity.
While her companions follow the reanimated corpses, the Doctor ends up being accused of witchcraft while confronting Savage over her hiding something. The Doctor attempts to reason with James before she is dunked, escaping her bonds at the last second while noting how Savage could not bear touching a tree used to dunk her. Once more confronted by the Doctor as the corpses arrive, Savage reveals that she was infected by the alien entity while chopping down the tree on the Hill. Savage assumed it to be deviltry and sought to cure it through the witch trials, accusing Old Mother Twiston as she knew of the infliction. The alien entity soon takes over Savage's body, revealing herself as queen of the war criminal race known as the Morax.
The Doctor discovers that Savage inadvertently damaged an alien prison system disguised as a tree, and designed to imprison the Morax within. Learning the Morax intend to have their king possess James before conquering Earth, the Doctor uses parts of the tree to save James and reactivate the jail. While the other Morax are forced out of their host bodies, the queen refuses to leave Savage's body as James kills them both. The following day, James declares to the Doctor that all records of the events will be erased before he and Willa watch in surprise as the group leave in the TARDIS.