The Doctor and Jo arrive on the medieval planet Peladon, where the Doctor is mistaken for the Earth Delegate of the Galactic Federation and Jo is mistaken for a princess.

The Doctor is convinced the Ice Warriors are trying to sabotage the conference but his attempts to prove it see him accused of sacrilege.

The Doctor is sentenced to fight Grun to the death and his attempt to escape leads to an encounter with Aggedor.

Hepesh's plan has been exposed but he is still determined to prevent Peladon joining the Galactic Federation by leading a rebellion against the King.

The planet Peladon, some time in the future. Mining disputes threaten the peace of the planet, and as the Doctor and Jo arrive, it seems that the ghost of Aggedor walks once more...

The Doctor is rescued by Gebek, prompting him to try and help the miners, but his advice results in Ettis launching another attack on the armoury.

The Doctor and Sarah pacify Aggedor and the Doctor encourages the Queen to make peace with the miners, but Ortron soon has him under arrest again.

The Ice Warriors take control of the planet and force the miners to return to work but Ettis takes the opportunity to try and destroy the citadel.

Sarah and Alpha Centauri decide to try and alert the Federation to what the Ice Warriors are up to but first they have to escape from the throne room.

The Doctor turns the Aggedor spirit against the Ice Warriors to aid the Peladonians in their battle but Eckersley attacks him with the security system.