100 minutos
The TARDIS arrives on the unnamed planet of the Gonds, who are ruled and taught in a form of self-perpetuating slavery by the alien Krotons — crystalline beings whose ship, the Dynatrope, crash-landed there thousands of years earlier after being damaged in a space battle. The Krotons are in suspended animation, in a crystalline slurry form, awaiting a time when they can be reconstituted by absorption of mental energy. Periodically, the two most brilliant Gond students are received into the Dynatrope, nominally to become "companions of the Krotons", but in truth to have their mental energy drained, after which they are killed.
Patrick Troughton
The Doctor
Frazer Hines
Jamie McCrimmon
Wendy Padbury
Zoe Heriot
James Copeland
Selris
James Cairncross
Beta
Gilbert Wynne
Thara
Philip Madoc
Eelek
Terence Brown
Abu
Madeleine Mills
Vana
Richard Ireson
Axus
Maurice Selwyn
Custodian
Bronson Shaw
Student
Roy Skelton
Kroton Voice
Patrick Tull
Kroton Voice
Robert La'Bassiere
Kroton
Miles Northover
Kroton
