And here we are in Episode Four. We're at the stage where there aren't many new characters or situations left to talk about, so this one's going to be quite brief.

To start off with, woo hoo, Private Parkinson is a new UNIT character. He'll probably die in that case. I don't know anyone called Parkinson so he's not named after anyone that I can remember.

Ooh, now here's this whole Kent/Sussex thing raising its head again. Surely a person injured in Smallmarshes (in Kent) wouldn't be taken to a hospital in Hastings (in Sussex)? More likely a hospital in East Kent.

Later during the UNIT sequence where Masie Hawk gets into civvies, we again get the hint that Smallmarshes is in Sussex. It's not, it's in Kent. Either mine or the Virgin copy-editor's geography was shot to hell. And whilst I'm often the first to accept such things on the chin, a quick glance at my initial drafts show, I did indeed get my geography right. Grrr…

One of the main reasons I'm so fond of Scales of Injustice is the human stories, especially Lethbridge-Stewart's. I really wanted to put the Brig through the wringer and show how whilst his orderly UNIT world is being shattered by the Doctor leaking things and his budget being cut by Geneva, his home life is falling apart in parallel. Poor bugger.

I like the idea he knows about Liz Shaw and Jeff Johnson but never mentions it until he has to. The reference to Gilmore of course refers to Remembrance of the Daleks, and Ben Aaronovitich's novelisation of the same that, if I recall, suggests his experiences led directly to the formation of unit.

When I worked at Marvel as editor of Doctor Who Magazine, it was often a seven days a week job, with a lot of (unpaid) late nights. I was lucky enough not to have a Fiona at home - but could well have had. The conversation Alistair and Fiona have over the phone was merely me imagining things that could easily have been levelled at me by my better half during my time there.

I loved the idea that he wonders if Kate was just a subconscious way of keeping his marriage alive and that he couldn't even bring himself to say anything more than a formal "sorry" to Doris Wilson on hearing of her husband's death. The Brigadier is a fascinating character who despite all this finds himself 'ready for action'. It was quite deliberate that it's Alistair throughout this entire scene until that final line where he becomes the Brig.

It's odd that this book seems to be about disintegrating relationships. The Liz scene suggests that she and the Doctor are world apart in outlook, and we already know she's having problems with Jeff. I'd recently gone through a breakdown of a relationship and must have transferred a lot of my feelings into this book. I doubt that I thought that then, but can see it clearly now.

Liz's friend Jan-Dick Heijs is based on a real Dutchman I knew. I think in the earliest sketchings I did for this story, Jana's character was a bloke and I called him Jan-Dick. When Jana turned into a woman, I used his name here.

When I wrote the final draft of this book, the tramp/man feeding them info - the UK equivalent of Woodward and Bernstein's Deep Throat - was written as 'Mister ?' but Virgin wouldn't do that and so the copyeditor went through and changed it to 'a friend'. I never understood why and I don't like it.

As Chuuk shows the Doctor around the base, we hear of the legendary two-faced, cowardly Masz K'll. That really was me working out my demons by naming an evil character after the man who'd pushed me out of Marvel. Hence Pannini and Tunbridge Wells (where they were based) get not very subtle digs as well. I like Chukk, the rejected genetic inferior reptile man (apparently) trying to prove he and his people are equal to the pure Silurians and Sea Devils.