Last updated 09 January 2020

Part Three

Part Three

Series Episode Number: 642

World Premiere: Sat 20 Sep 1986 - 5:47pm BST [BBC One] (United Kingdom)
First Broadcast: Wed 10 Jun 2015 - 8:00pm EDT [Retro TV]
Running Time: 24 minutes 18 seconds

3.90 Million (UK)

Appreciation Index: 70 (UK)

Chart Position: 98 () (UK)

With the black light converter destroyed, the Doctor fears for the planet's safety and needs to find the Secrets of the Sleepers and discover why they are there.