Parts: 1 (60-minute)
Writers: Steven Moffat
Airdates: 25 December 2016
Production Code: n/a

Doctor: twelfth
Companion: Nardole

Creature Feature: the Shoal

Story: Attempting to untangle the temporal distortion around New York City, the Doctor enlists the help of eight-year-old comic-book fan Grant Gordon... who unwittingly scuppers the Doctor's plan by swallowing its key component, the Hazandra gemstone, believing it to be cold medication. Instantly, the gemstone's ability to make a person's wishes come true is transferred to Grant himself... and Grant's deepest wish is to have superhero powers.

Twenty-some years later, Grant has decided to use his powers for good, and roams New York as the superpowered vigilante Ghost, saving innocent civilians in his free time while working as the underappreciated nanny for his middle-school crush. And when the Doctor reappears in his life, hot on the trail of an alien plan to conquer the Earth, Grant might just be his secret weapon.