Planet (The Savages)

An Earth-like planet was once home to the civilised Elders and the primitive Savages. The Elders survived by draining energy from the Savages who lived outside their city. The First Doctor put an end to this practice. His companion Steven Taylor remained behind to help unite the two peoples. (TV: The Savages, PROSE: The Man in the Velvet Mask)

A Sontaran scout ship crashed on the planet several years before Steven was transported to an alternative Death Zone on Gallifrey by Borusa. This experience taught him a Sontaran could be incapacitated by striking his probic vent. (AUDIO: The Five Companions)