The Doctor returns to Peladon, some fifty years after his first visit (The Curse of Peladon). King Peladon's daughter, Queen Thalira, is now in charge, advised by the inevitable Evil Chancellor, who promptly arrests the Doctor and Sarah Jane. Alpha Centauri, the effeminate octopoid from the last story, is now the Federation ambassador to Peladon, and clears the Doctor's name. The rival power bloc surrenders to the Federation and the Queen offers the Doctor the chancellorship, but the Doctor suggests Gebek, the miners' leader.