Part OneSeries Episode Number: 640
World Premiere: Sat 6 Sep 1986 - 5:46pm BST [BBC One] (United Kingdom)
First Broadcast: Sun 27 Nov 1988 - 11:00pm CST [WTTW 11 Chicago]
Running Time: 24 minutes 57 seconds
4.90 Million (UK)Appreciation Index: 72 (UK)
Chart Position: 69 () (UK)
Placed on trial by his peers, the Doctor is forced to watch events from his past, beginning with an incident on Ravolox involving the curiously named Marb Arch.