The planet's real name is Kastopheria, but generally it's been rechristened Catastrophea — it's a catastrophe waiting to happen. Supposedly civilised races are exploiting the world, squabbling over its wealth and resources, while the indigenous population — golden-skinned giants — seem not to care what their own fate might be. The Doctor and Jo soon become embroiled in a plan to keep peace between different parties vying for control over the planet.