Man, this one hard to get through. A couple good ideas, like the metamorphosis being supposed to happen and the whole colonialism+Apartheid analogy, but God the characters were terrible and the science (particle inversion?) was noticeably wonky, too silly even by DW standards. I think this story would work better as a tighter 4-parter rather than the 6-parter it is. I lost count on how many times they go from the planet surface to the Skybase and back again. The main villain, the Marshal, was just so over the top evil and despicable his motives weren't even interesting, and his communicator stick thingy was dumb. This is the first Pertwee story that didn't click with me, which is a shame.