The TARDIS materializes on a distant planet in the far future, which is inhabited by the Elders—an advanced, idyllic civilisation—and bands of roving savages. The Elders call The Doctor “The Traveller from Beyond Time” and welcome him with open arms. They know who he is and much of his history and shower the travellers with gifts. Dodo, however, finds out that the Elders are only able to obtain the energy they need by draining the life-force of the savages.
When The Doctor tries to put a stop to this, he is subjected to the energy drain, his life-force being transferred into the body of the leader Jano (Frederick Jaegar). But the time-lord’s powerful personality tries to take over Jano. Dodo and Steven venture outside the city and meet the savages, who protect them from the soldiers who are searching for them. The savages were once a skilled and artistic race.
Returning to the city, they find the Doctor in a weakened condition and help him escape. They help the savages to fight back and change the nature of Elder society. Steven decides to stay and help rebuild the civilization.
There is nothing left of this simple story but for some still pictures and fragments.