In this episode of Doctor Who, we find humans in the year 3000 who have dominion over the planet Solos. The native Solonians are subjugated. Earth is planning to leave Solos, but Earth’s Marshall of Solos is a maniacal genocidal asshole.
The Solosians are mutating into insect-like creatures. Of course they don’t know what’s going on, and The Doctor has to tell the Solosnigans that it’s a natural occurrence.
They were trying to do something interesting… talk about colonial issues, but unfortunately they never quite hit the nail on the head. The native population is talked down to by everyone, Earthlings and Time Lords alike. The Solosians are not listened to or treated with respect. A human scientist, on their side, is the authority figure on Solosers.
Much like a lot of Doctor Who, this story’s failing is just how British the show is.