Catastrophea
Terrance Dicks
 The Doctor and Jo arrive at a planet named Kastopheria. Its natives are peaceful, golden-skinned giants who seem not to care that other races are exploiting their world for all it is worth. Said races are coming into conflict with each other, a problem the Doctor and Jo try to solve. The possibility of peace is disrupted by the war-mongering Draconians. In trying to quell the planet's problems, the Doctor risks uncovering a force that threatens the entire galaxy.