I called the planet known on the Doctor Who TV series as ‘New Earth’ Gantus III in the story Moondust, which also introduced Gordo and Petra McDevitt, the Felinites, travelling in their space equivalent of a covered wagon to start a new life there. Felinite is also my invention as a race name for the cat people. I called them McDevitt because the cat in the TV episode Gridlock was called Brannigan and had an Irish accent, so it seemed like an interesting idea to make the Felinite townspeople all Irish or Scottish. The little joke about McDuff and MacDonagh fitted in very nicely then.

Since a lot of Scots and Irish immigrants were pioneers in the American West, this made perfect sense when I decided that Gantus III in this pre-Human era would resemble ‘Walnut Grove’ in the TV series Little House on The Prairie, which is a reasonably typical, or stereotypical, frontier town. In point of fact, Walnut Grove in Minnesota was only one of the townships where the REAL Ingalls family lived in the original books. They settled eventually in a place called De Smet in South Dakota. But I think it is more likely that somebody like Donna, whose life before she met The Doctor was driven by popular culture rather than literature, would know the TV version rather than the book version.

Gordo’s milk bar is based on a very vague memory of a small café in Leyland, Lancashire, that I remember going to when I was very young. It had rows of seats along the counter and cold milk was served from a dispenser behind the counter. I doubt if it’s there any more. It’s probably a fast food franchise now.

The infection that turns the cats into savages is, as a few readers guessed, based on the infection that the Cheetah people of the Sylvester McCoy story Survival passed onto Humans. A few online forums have speculated about whether the Cheetah people might be the forebears of the more civilised cat people of New Earth. And why not?

I did intend to have something going on with the alcoholic beverages being sold at Murphy’s and something about the tension between the teetotal settlers and the rougher elements that frequent the saloon. But really that would have been a different story. It might even be one I can do at a later date. I also intended to have more going on with Doctor Phelim O’Rourke, the town’s medic. I think there is definitely room for a comeback story here.