Death in New Manhattan’s main idea comes from a horror novel called The Fog, by James Herbert – not to be confused with the film by the same name, which is nothing like it. In the novel, an accidental chemical spill causes people to go insane, killing each other in various dreadful ways. There is a particular scene where a man gives his family overdoses of sleeping pills to ‘protect’ them from the insanity, and I never found the idea of people just dying in that way satisfactory, so in my version, The Doctor is on hand to save them all.

I had a different source for the psychosis. An insect that burrows under the skin and causes the chemical reaction. Looking back on the story in late 2007 it occurs to me that the silver ball they came to Earth in is not unlike the Toclafane balls from Sound of Drums/Last of the Time Lords. But then there are few things new in science fiction. It’s all just a matter of finding different ways of telling the same story.

And that was the idea, here. There are plenty of ‘masses of people going insane’ plotlines. The James Herbert one is only the tip of the iceberg. My version differs mainly because The Doctor is there as an ocean of calm and safety for everyone.

There WAS a lot of violence going on in this story. Not directly described, but the aftermath that The Doctor walks through in the park, with a dismembered body hanging from a tree, does give the impression of something quite gruesome having occurred. I did consider toning it all down a bit, and simply having people lying in the park with bad hangovers and embarrassing flashes of memory, but it really didn’t work. The threat of a really terrible fate if The Doctor didn’t get rid of the death bugs had to stand. It makes it one of the rare stories that possibly wouldn’t be suitable for 7pm viewing. Although, that said, gruesome things happen to people at 7pm. People are killed and skinned by Slitheen, they have their bodily fluids drained and are left as husks by the Lazarus monster. And what happens to people in the hands of cybermen and Daleks is utterly gruesome. So perhaps not.

The Doctor has an extra problem in this story. Having cured everyone with his aerosol that kills the larvae under the skin, he finds there is somebody missing, a down and out called Solly. New New York has poverty just like New York. Solly and Princess Peggy, the female down and out who alerts The Doctor to the problem are the underclass of New Earth. At the start of the story, Alec comments that old problems come along with the old name.

Princess Peggy claims to be of Gallifrey. Obviously she isn’t. The Doctor takes her in good humour, recognising that some people live in their dreams. There was a good deal of feedback, though, asking if Princess Peggy would be back, and what WAS her story. So, of course, she does return in a later story.

http://readers.penguin.co.uk/nf/shared/WebDisplay/0,,214113_1_12,00.html