The Doctor and Clara, with their old friend Rigsy, find themselves in a magical alien world, hidden on a street in the heart of London.
Sheltered within are some of the most fearsome creatures of the universe… and Ashildr (Maisie Williams)! With a death sentence hanging over their heads, not all of the intruders will get out alive.
Writer: Sarah Dollard. Director: Justin Molotnikov. Producer: Nikki Wilson
Cast: Peter Capaldi and Jenna Coleman
Guest cast: Maisie Williams, Joivan Wade, Naomi Ackie, Simon Manyonda, Simon Paisley Day, Letitia Wright, Robin Soans, Angela Clerkin, Caroline Boulton, Jenny Lee.