This week's Doctor Who begins in 1380, Aleppo, and Tahira (Aruhan Galieva) is rushing home. But the hospital where she lives it beset by alien creatures. She's tried to warn Maryam (Sirine Saba), but no one believes her, until its too late. Meanwhile, the Doctor has taken her fam home to present-day Sheffield for a 24-hour visit home. But as soon as her friends disembark, a figure appears in the dark (Ian Gelder). (Torchwood fans, you recognize him.) He dematerializes almost instantly, just as the TARDIS flashes up a warning about Aleppo. Figuring she's got time to nip off and see, and be back by tomorrow lunchtime for the pickup, the Doctor takes off.
The Doctor: I've got plans crashing through m brain all the time. You want a plan? Come to me. Identifying which plan's going to work? That's the tricky bit.
Yaz heads home for lunch with her sister, Sonya. Ryan pops round to see his buddy Tibo (Buom Tihngang), only to discover his mate's gotten right paranoid since they last saw each other. And Graham heads over for a spot of cards with his mates, but as he deals out the cards, visions of the Time Vortex, planets, and a woman (Clare-Hope Ashitey) crying, flood his brain. She whispers: "This is what he did to me. Help me." And he's not the only one seeing things. Tibo's been having nightmares, someone in the dark is watching him. He's seen a man around the neighborhood, watching him from street corners, who has even appeared in his flat.
Tibo's surprised Ryan takes him seriously, but grateful. Ryan agrees to stay the night in case the man appears again. Yaz also has nodded off, dreaming of a deserted road, her sister, and a cop. When she wakes up, the same man who appeared in the TARDIS is there. He dissipates, only to reappear at Tibo's. Ryan wakes up and sees him too, and is horrified to see the man's fingers have detached, one of which is in Tibo's ear. Ryan yells, and the man dissipates again, taking Tibo with him.
Over in Aleppo, the Doctor soon finds Tahira, who warns her to run. There's still one creature left on the ceiling. It threatens the Doctor, but Tahira somehow orders the creature to leave her alone, and it obeys. As the Doctor tries to get a bit of context and backstory out of the girl, her phone starts ringing off the hook. All three companions are calling in various states of panic. She brings Tahira on board the TARDIS to pick up everyone else. Yaz and Ryan agree they saw the same man, but Graham's vision of the woman seems completely separate. The Doctor hooks him into the TARDIS mainframe, it responds by taking them somewhere in deep space, far in the future.
It's an observation platform, observing a planetary collapse, except the planets aren't collapsing. They're being held apart by a (relatively) tiny orb. It's the same one Graham saw in his dream. Whoever the woman is, she's inside that orb. Yaz looks up and sees fingers, hundreds of detached fingers, broadcasting into the orb. As the Doctor spouts technobabble, Tahira wanders off. She finds Maryam imprisoned, asleep, while the creatures that attacked them are in cages. The man once again appears. He says they are "Chagaskas," and they are "her worst fear." As the companions race in, his fingers once again detach and attack.
As for the Doctor, the man comes to her. He finally introduces himself as Zellin. She knows that name. Zellin was supposedly a mythical creature, thought to be a god. Zellin is amused. He's not a god, but plays with the humans; they fascinate him endlessly, as do their painful, terrifying nightmares. The Doctor believes she can defeat Zellin by freeing the woman in the orb, but it turns out she's got it the wrong way round. The woman is Rakaya, his partner. The dreams aren't feeding him, but her. Zellin and Rakaya tortured the peoples of these two planets until they banded together, trapping her between their worlds. All the Doctor did was unleash another monster and become imprisoned too.
Dreams are what this is all about. Yaz is still on the road, with Sonya telling her no one is coming to help. Ryan is surrounded by flames with Tibo, now an old man, accusing him of abandoning his mates. As for Graham, he's back in the hospital, with an IV hooked to his arm. Grace is there, as his nurse, not his wife. She addresses him as Mr. O'Brien, saying his cancer's returned. He has hours to live. Then she rounds on him: "Why didn't you save me?" The Doctor dreams of the Timeless Child. Meanwhile, Rakaya demands to go to earth, where she can slowly feast on dreams for centuries.
But thankfully, once the gods have gone, the Doctor awakens and releases her friends, as well as Tibo. Before Rakaya and Zellin can put the world to sleep, she entices them back to Aleppo with the Chagaskas, which Rakaya has never seen. But having confronted her fear of them, Tahira can control the Chagaskas. (They are hers, after all.) And the Doctor and her fam can control the Gods once they face them down too, retrapping them inside the orb together, forever.
But the fears remain. Yaz recalls the moment that was the basis of her nightmare. She was in high school, running away. The cop, Antia Patel (Nasreen Hussain), found her after Sonya called her in as missing, and promised Yaz it would get better. Yaz has to admit, Anita was right. Graham admits he fears every day that remission will end, and this will all have been an intra-cancer period. As for Ryan, he's starting to wonder how long the fam can keep riding. How long until it's time to go back to his life, which is passing by without him.