Treasure of Ioza III began with an article that appeared online in various sources in the autumn of 2008 about the amount of space junk around planet Earth. It is already quite remarkable how much of a ‘barrier’ there is forming around us. I immediately started to think about the extreme scenario if a planet allowed itself to be hemmed in completely by metal debris outside its atmosphere. The result, surely, would be something like the frozen Earth scenario of films like The Day After Tomorrow or Deep Impact.

I had no intention of doing that to Earth, though, so of course it would happen on another planet and be a cautionary tale for Donna as The Doctor showed her the consequences for Ioza III. The name of the planet is not significant in any way, incidentally. I use a random planet name generator.

I obviously needed a plot to go around this planet. And then I hit on the idea of a reunion with Sabalom Glitz and Mel Bush. Because the one thing Glitz can’t resist is a treasure hunt.

The idea that the treasure was, in fact, the children of Ioza came to me next. I toyed with the idea of them being in a race bank such as we saw in Four to Doomsday or some other non-corporeal form, but really, suspended animation, cryogenic freeze or some variation thereof, works better. It has been done before, of course, most successfully in the Tom Baker Doctor Who episode, Ark in Space. This is a variation on the theme.

The idea is slightly based on Deep Impact, where a selected group of people plus works of art and treasure were going to be hidden in deep caverns in order to preserve Human civilisation – well, American civilisation, anyway. This is a variation on the same theme.

After that all came together, the rest was easy. The TARDIS falling down the shaft, with the two women safe and well inside, while the two rent-a-thugs fell to their deaths outside was a detail that came together as I was writing.

The idea of Glitz and Mel adopting one of the Iozan orphans was a final touch I decided would round things off nicely. Mel had managed to marry Glitz. But now she managed to domesticate him. Of course, he gets some of the treasure into the bargain! Will he behave? Will suburbia suit him? Who knows.