Part ThreeSeries Episode Number: 544
World Premiere: Sat 17 Jan 1981 - 5:11pm GMT [BBC One] (United Kingdom)
First Broadcast: Wed 1 Apr 2015 - 8:00pm EDT [Retro TV]
Running Time: 22 minutes 15 seconds
8.30 Million (UK)
Chart Position: 59 () (UK)
Recorded on Thu 02 Oct 1980 in Television Centre 1
As the void begins to shrink around them, Rorvik plans to take desperate measures to escape through the mirror. The Doctor discovers the dark secret of the Tharils' past.