Part FourSeries Episode Number: 533
World Premiere: Sat 18 Oct 1980 - 5:44pm BST [BBC One] (United Kingdom)
First Broadcast: Sun 24 Sep 2017 - 5:30pm EDT [Retro TV]
Running Time: 19 minutes 30 seconds
4.70 Million (UK)Appreciation Index: 63 (UK)
Chart Position: 127 () (UK)
The Doctor must convince the Tigellans of his innocence if he is to prevent Meglos from using the dodecahedron to destroy their world.