I just want to point out something.
You know how we're always there to criticize an episode? Whether it's a poor reader, bad hardware setup or just not enough time to clean up the final audio?
Well, this episode deserves the opposite. I want to congratulate the EP team. This story was well-paired with the reader, and very well read. That accent! In my opinion, it made the episode. I'll be honest, at first my American-trained ears had a little trouble keeping up, but I slipped into the rhythm of it pretty quickly. It reminds me a little bit of the Hitchhiker's Guide radio plays. They are still my favorite form of the trilogy (in five parts), even though I was exposed to them after the books. It somehow added an extra dimension of hilarity to the story, very Adams-esque.
Only in an Adams universe would nano robots give up trying to terraform an asteroid and instead do it to planets. Only in such a universe would antigravity space ships need an all powerful space navy to fix their own blunders. (BTW, if you do happen to have some form of gravity-neutralizing thrust, that is a very powerful weapon. Drop a planet into its star or throw ships out of the galaxy. The things you could do are limited only by your imagination. Which, I suppose, nanobots probably don't have. Never mind).
I also totally missed the Oz references until the wizard showed up, but the story stood well enough on its own without them.
I'm sort of glad that Dot chose to watch the end. As Dumbledor said: "To the well organized mind, death is but the next great adventure."