A crash landing involving the TARDIS brings "The Doctor" (Tom Baker) and "Romana" (Lalla Ward) into contact with a group of attractive young people being moved to a maze intended as a sacrificial site for the "Nimon." This creature is meant to be venerated at the direction of "Soldeed" (Graham Crowden), who seeks to maintain access to advanced technology that will enable the establishment of a second "Skonnon" empire…