The Doctor (Jodie Whittaker) drops her companions off in Sheffield to spend time with their friends and family while she responds to an alert from Aleppo, Syria, in 1380. She saves Tahira (Aruhan Galieva), the last surviving patient in the Bimaristan Arghun Mental Hospital, who is threatened by a nightmare creature. But her companions are having dark visions of their own. Graham (Bradley Walsh) sees a woman pleading for help, Yaz (Mandip Gill) has nightmares about a man in dark clothing, and Ryan (Tosin Cole) sees a man detach his fingers and place them in the ears of his friend Tibo (Buom Tihngang). They all call the Doctor simultaneously.
She uses the TARDIS’s telepathic controls to track down Graham’s vision, which is near a spacecraft lodged between two planets. There is a prison inside with a quantum fluctuation lock. There are signals sent from Earth to the prison in detached fingers. As the Doctor manipulates the lock, the others are captured by a man in dark clothes. He is the immortal god Zellin (Ian Gelder) and thanks the Doctor for rescuing his friend Rakaya (Clare-Hope Ashitey), another immortal god in the prison. They are gods of chaos and set the planets against each other until Rakaya was trapped. The nightmares from Earth were to keep Rakaya sane.
Zellin and Rakaya trap the Doctor and take off for Earth to feed on all our nightmares. The Doctor escapes and learns how to use Zellin’s fingers. Knowing that the nightmare creature in Aleppo cannot harm her, she lures the gods there and traps them. The companions return Tahira to her time and return to Sheffield. Ryan promises to stay in touch with Tibo, Yaz thanks a police officer who helped her in the past, and Graham confides in the Doctor about his cancer scares. As the companions talk about their future with the Doctor, she announces that they are going to visit Mary Shelley.
The episode was written by Charlene James and Chris Chibnall and directed by Emma Sullivan, and it was met by mixed reviews. Zellin mentions the Celestial Toymaker from the First Doctor’s reign, the Guardians from the Fourth and Fifth, and the Eternals from the Fifth. Ian Gelder had appeared in Torchwood: Children of Earth. The story was criticized because the Doctor seemed insufficiently sensitive about Graham’s fears, but others identified with her difficulty. I’m not sure how I would expect an immortal Time Lord to identify with my cancer fears, frankly, particularly since she just lost her entire world. Again.