Parts: 2 (45- & 60-minute)
Writer: Steven Moffat
Airdate: 24 June — 01 July 2017
Production Code: n/a

Doctor: twelfth
Companions: Bill, Nardole

Megalomaniac of the Week: Missy
Creature Feature: Cybermen

Story: In order to test Missy's real-world response now that she's attempting to turn over a new leaf, the Doctor unleashes her on a futuristic spaceship emitting a distress call. With Bill and Nardole as her reluctant assistants, Missy irreverently steps into the Doctor's shoes and quickly discovers that the ship is struggling to escape the pull of a nearby black hole.

The ship initially seems abandoned, but the new TARDIS team quickly discover that it's not: the crew's alien janitor soon appears, terrified of creatures from the bowels of the vessel who stormed the bridge and abducted all of the human crew just after the ship was stranded. And when the lifts begin to rise again, he realizes that the creatures are returning for Bill...