The "Doctor" (Tom Baker) and his new pal "Adric" (Matthew Waterhouse) are parked above the planet of "Traken" when it's throned and elderly keeper visits them in the TARDIS. He's a bit of a harbinger of doom, but still asks the time lord to come to the planet to help avert a bit of nastiness with the statuesque "Melkur". No sooner have they arrived, though, then they are suspected by the locals of being the epitome of evil, and it's clear that the scheming of "Melkur" is already well under way - and that he has a fifth columnists from amongst the hierarchy of councillors to help with his deviou...