On the planet Dido, the monstrous Koquillion terrorizes Bennett and Vicki, the only survivors of a crashed spaceship. When the TARDIS lands, the Doctor, Ian, and Barbara team up with Vicki to discover what Koquillion is hiding. (Originally broadcast in two parts.)
Quest roles:
Maureen O'Brien(Vikki), William Russell(Ian Chesterton), Jacqueline Hill(Lexa)