I got to work, intending to write a novella that would sit chronologically between the stories in the collection and Pariah, the first Bequin book. I took a look at the stories ready for inclusion, and worked out the best running order, and in doing so, suggested to Nick that there were three other old short stories that might be nice to include. These weren’t Inquisitor stories at all: they didn’t feature Eisenhorn or Ravenor or anyone else from those books. But they were stories I was very fond of, and I felt they would fit. They were all detective stories, procedurals, and they were also ‘domestic 40K’, which is the joke term we use to describe the Eisenhorn books – stories set AWAY from the battlefronts of the Warhammer 40,000 universe, stories about the planets and cities and people that the wars of 40K are trying to protect. If those three stories were going to be collected together anywhere, then an Eisenhorn anthology was the ideal place, if nothing else because they were examples of me exploring the writing method that I use in the Inquisitor books.

Then the accident happened. I began to think of ways of obliquely connecting most of the old stories, even the non-Eisenhorn ones, to the new novella. This appealed – rather than the stories being unrelated vignettes and incidents from Eisenhorn’s career, they could be brought together by the novella to make a volume that was satisfyingly linked by themes and ideas.

And the novella was no longer a novella. I think I realised that around the 20,000 word mark. I warned Nick it was ‘running a bit long’. He told me to carry on regardless. Three weeks later, I had a full-length novel. That’s The Magos, which forms the last part of this volume. It’s a brand new, entirely original Eisenhorn novel. It happened by accident, refusing to admit it was a novel even while I was writing it. It wraps the old stories in this anthology up in its arms and acts as a (major) prologue to Pariah.

It also, contrary to plan, becomes the entirely unintentional fourth novel in the Eisenhorn trilogy. Like I said, accidents happen.

So, this book contains old stories you may have read before, stories that have not been in print before, stories that you might not think of as belonging here, and a brand new Eisenhorn novel. Even if you have read (or heard, as audios) the old stories in this book before, I suggest you don’t skip them. When you reach The Magos, the effort of revisiting them will be rewarded.