Series: 9
Original Air date: November 28, 2015
Number Doctor: 12th
Companion(s): Clara Oswald
Writer(s): Steven Moffat
Director(s): Rachel Talalay
Guest Stars:
Jami Reid-Quarrell as Veil
Synopsis: The Doctor, alone and depressed, finds himself inside a nightmarish castle seemingly created to terrify him. However, as the Doctor soon finds out, everything is not quite what it seems to be. The Doctor must solve the riddle of his prison in order to find out where he is and why he is there.