The Mysterious Planet

143a – The Trial of a Time Lord: The Mysterious Planet
Doctor Who serial
The Doctor and Peri discover the ruins of Marble Arch tube station on the planet Ravolox
Cast
Doctor Colin Baker (Sixth Doctor)
Companion Nicola Bryant (Peri Brown)
Others Lynda Bellingham — The Inquisitor Michael Jayston — The Valeyard Tony Selby — Sabalom Glitz Joan Sims — Queen Katryca Glen Murphy — Dibber Tom Chadbon — Merdeen Roger Brierley — Drathro David Rodigan — Broken Tooth Adam Blackwood — Balazar Timothy Walker — Grell Billy McColl — Humker Sion Tudor Owen — Tandrell
Production
Directed by	Nicholas Mallett
Written by	Robert Holmes
Script editor	Eric Saward
Produced by	John Nathan-Turner
Executive producer(s)	None
Incidental music composer	Dominic Glynn
Production code	7A
Series	Season 23
Length	4 episodes, 25 minutes each
Originally broadcast	6 September–27 September 1986
Chronology
← Preceded by Followed by → Revelation of the Daleks The Trial of a Time Lord: Mindwarp
List of Doctor Who serials

The Mysterious Planet

Author	Terrance Dicks
Cover artist	Tony Masero
Series	Doctor Who book: Target novelisations
Release number	127
Publisher	Target Books
Publication date	19 November 1987 (Hardback) 21 April 1988 (Paperback)
ISBN

The Mysterious Planet is the first serial of the 23rd season in the British science fiction television series Doctor Who, which was first broadcast in four weekly parts from 6 September to 27 September 1986. It is part of the larger narrative known as The Trial of a Time Lord, encompassing the whole of the 23rd season. The title The Mysterious Planet is not used on-screen and only appears in the serial's scripts with the four episodes that comprise the story being transmitted as The Trial of a Timelord Parts One to Four.

Events of the serial are framed on an arcing plot that carries through the other three serials of the 23rd season. In this, the Doctor is forced to land the TARDIS aboard a Gallifreyan space station, where he is brought into a courtroom. The Inquisitor informs the Doctor he is on trial for conduct unbecoming a Time Lord; evidence will be presented by the Valeyard. The first evidence is shown through video footage, taken from the Matrix, of the Doctor's recent involvement in the planet Ravolox, where the Valeyard shows that the Doctor willingly became involved in the affairs of the planet. The Doctor denies these charges as the Valeyard brings them. After showing the video, the Valeyard affirms he has more evidence sufficient to call for the end of the Doctor's life.

As shown by the court evidence, the Doctor and Peri land on Ravolox, both noting a similarity to Earth. The Doctor is aware that Ravolox was devastated by a fireball, according to official records, but the presence of flourishing plant life make him suspicious. As they walk, they are observed by Sabalom Glitz and Dibber, mercenaries on the planet attempting to destroy a "black light" generator in order to destroy the L3 robot deep underground that it powers. The Doctor and Peri find a tunnel and enter to find remains that appear to be that of the Marble Arch tube station on the London Underground Central line, piquing the Doctor's curiosity further. The Doctor wishes to proceed deeper, but Peri is worried and stays behind.