The TARDIS arrives on the planet Marinus on an island of glass surrounded by a sea of acid. The travellers are forced by the elderly Arbitan to retrieve four of the five operating keys to a machine called the Conscience of Marinus, of which he is the keeper. These have been hidden in different locations around the planet to prevent them falling into the hands of the evil Yartek and his Voord warriors, who plan to seize the machine and use its originally benevolent mind-influencing power for their own sinister purposes.
John Gorrie
Director
Terry Nation
Writer

William Hartnell
The Doctor

Carole Ann Ford
Susan Foreman

Jacqueline Hill
Barbara Wright

William Russell
Ian Chesterton

George Coulouris
Arbitan
Martin Cort
Voord / Warrior / Ice Soldier / Aydan
Peter Stenson
Voord / Ice Soldier / Second Judge
Gordon Wales
Voord

Robin Phillips
Altos
Doctor Who: Deep Breath77%
Stargate: Continuum71%
Stowaway60%
Valerian and the City of a Thousand Planets66%
Solo: A Star Wars Story65%
Titan A.E.66%
Earth to Echo58%
Doctor Who: The Day of the Doctor81%
Timescape64%
The Man Who Fell to Earth64%
Star Trek: Insurrection64%
Star Trek: The Motion Picture64%
Star Wars: The Rise of Skywalker62%
Serenity73%
Forbidden Planet72%
Halo: Nightfall67%
The Creator70%
Stargate SG-1: Children of the Gods72%
Interstellar84%
Stargate70%