There's nothing "only" about being a girl.
— Sarah Jane Smith
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.
A spectral image of Aggeddor (the titular Monster, a sacred monster to Peladon) has been blamed for a number of deaths among the Trisilicate miners. The Doctor discovers that the spectral image is the work of a human engineer, Eckersley, who is working in cahoots with some renegade Ice Warriors to seize the Trisilicate deposits for a rival power bloc.
The Ice Warrior leader, Azaxyr, leads an attack on the throne room, but is killed along with his comrades when the Doctor turns Eckersley's heat ray on them. Eckersley takes the queen hostage, but the Doctor and the real Aggeddor hunt him down. Eckersley is killed, but so is Aggeddor.
The rival power bloc surrenders to the Federation and the Queen offers the Doctor the chancellorship, but the Doctor suggests Gebek, the miners' leader.
- Agony Beam: The refinery's security system.
- Continuity Nod: There are numerous mentions to the previous Peladon story.
- Enemy Mine: Ortron and Gebeck's striking miners after the Ice Warriors show up.
- Evil Chancellor
- Flat Earth Atheist: Vega Noxos (who belong to the Satyr alien race known as the vegan) He viewed the native Peladonian miners as "superstitious primitives" for their fear of Aggedor. Ironically he was killed by the fake ghost of Aggedor.
- Heel Face Turn: Chancellor Ortron
- Les Collaborateurs: Eckersley conspires with the Ice Warriors for a stake in the trisilicate trade.
- The Mole: Eckersley.
- Multicolored Hair / Skunk Stripe: The miners' hair, which has alternating bands of white and brown.
- Presumably a genetic trait of the natives of Peladon, given that it's the same or similar with everyone else who's from the planet.
- Human Aliens
- The Revolution Will Not Be Vilified: Both averted and played straight; Gebeck's worker's rights movement is depicted sympathetically, but the attempts of Ettis to start an actual revolution are universally condemned.
- Ripped from the Headlines: This story was inspired by the 1972 miners' strike.
- Scooby-Doo Hoax
- Sequel Episode: To "The Curse of Peladon".
- Strongly Worded Letter: Alpha Centauri threatens to make their displeasure known by sending an official communication to the Galatic Federation. This is during the middle of an armed uprising against the government.
- Viewer Gender Confusion: Alpha Centauri, an alien hermaphrodite, who has an obviously female voice and mannerisms but is usually referred to as "he".
- What's Up, King Dude?: It seems anyone, including miners, can walk into the throne room and talk to the queen whenever they want to talk to her about something.
- The X of Y
- Yellow Rocks - Trisilicate