(This is going to be a slightly abbreviated discussion, because I discussed the book's ideas at length in the supplementary essay bundled with it, and answered a number of questions about it in the blog entry immediately preceding this one.)
So what's left to say ...?
Rewind the clock to 1993. I was living in Watford, part of the suburban sprawl that surrounds London proper, working for a Californian software multinational and not writing enough fiction. One of my problems was starting stories and not finishing them. One of the starts I made, was this rather weird, chillingly distanced third-person-omniscient vision of a CIA photographic analyst in a world where the cold war produced even more baroque technologies than in our own: his memories of a childhood visit to an air show where nuclear-powered NB-36s were on display (in our universe, the NB-36 program was cancelled before anything flew under actual nuclear power, as with the Soviet Tu-95LAL (the follow-on Tu-119 never flew either)). His memories merge with his angst as he pores over recon imagery of .... what?
Forward to 1997. I'd read a short story by Bruce Sterling, The Unthinkable. It's a short throw-away in which a pair of arms negotiators are reminiscing about how they agreed to back away from the precipice and cut the Cold War horror arsenals by ditching the
ICBMs and Hydrogen bombs chained Lovecraftian horrors ... and I suddenly realised what my analyst was looking at. I'd also been re-reading "At The Mountains of Madness" and decided, in classic naive non-metaphorical science fictional mode (where a rocket ship is just a rocket ship every time) to tackle the alienation and ennui engendered by constant exposure to the threat of annihilation, and also to make the Mythos frightening again by linking Lovecraft's horrors (by then reduced to the stuff of silly jokes and plush bedroom slippers) to a terrifying reality that had only receded into the background in the past few years.
The result was a story titled "A Colder War". I sold it, and it garnered quite a bit of attention—I get a reprint request pretty much every year.
Fast-forward to 1999. I'd finished working on "Festival of Fools" (aka "Singularity Sky") and it was on its way to an editor's in-tray. I'd written "Lobsters" and it was doing the rounds ("meritless, vapid, style-obsessed trash" said the rejection letter from the first editor I sent it to, he who had just bought "A Colder War": there's no accounting for taste). I needed a novel-length project and I had bits of the wreckage of "The Harmony Burn" to cannibalize (this was the unpublishable novel from 1994-96—unpublishable for structural/characterisation reasons, not because publishers are stupid). Secret government agencies dealing with the suppression of hard take-off singularities seemed a bit dubious to me by then, but I'd just sold "A Colder War" and, while that particular story was far too bleak to work with, the idea of rebooting the Lovecraftian/spy nexus appealed. So I began writing. And the first thing I came up with was Bob, mentally swearing at his boss as the rain trickles down the back of his neck and he tries to break into an office I used to work at in Watford to steal a deadly thesis.
At which point everything was hopelessly cross-infected by my memories of the Kafkaesque bureaucracy inside that particular company's technical publications department. And then I had Bob go back to work the next day in a grim little civil service office maze not unlike to one I'd spent three months working in as a contractor in 1996. Both jobs were so soul-destroying that you had to view them as black farce in order to work there: the software company, for example, was the one where whenever senior executives came to visit our managers would trawl the cubicle farm first thing in the morning to take down all the Dilbert cartoons pinned to the walls.
I was working in a dotcom startup at the time, and spending too much time reading Slashdot. And it occurred to me that the staid British civil service would have serious indigestion if it tried to swallow a Slashdot-era dotcom geek. But what if the bureaucracy in question wasn't allowed to fire him? There's scope for comedy there, the comedy of dissonance: round peg in a square hole, and so on.
So there you've got the ingredients. Lovecraftian horror; the secret agency dedicated to protecting us from the scum of the multiverse: the protagonist (Bob, a put-upon hacker who is an utterly inappropriate hire but who can't be gotten rid of): the cold war ambiance: the dark humour. I probably ought to mention the novels of Len Deighton, which I was re-reading at the time—one of the most significant of the British cold war thriller writers.
The whole thing snowballed into a short novel. In early 2001 I sold first serial rights to the same small Scottish magazine who'd published "A Colder War" and "Antibodies"; it ran in Spectrum SF issues 7-10 after John Christopher's last novel and was read by maybe a thousand people. (Thereafter, Spectrum SF ceased publication. I like to think I didn't kill it.) This was my first published novel, and I sold it myself; my agent's first reaction when I sent it to her was, "this is great fun but it'll be impossible to sell: it's far too cross-genre". She was, in fact, quite correct ... for a non-name author in 2001.
The rest is history, although it's a rather weird history: at some point I'm going to have to write down the tortured publication track of the first four Laundry novels just to provide some context, just to show that rules are for breaking. This series broke all the rules of publishing and somehow prospered, never mind merely surviving—even though the dice were stacked against it from the beginning.
But that's enough for now. (I've just finished the first draft of a new Laundry novella, set between "The Jennifer Morgue" and "The Fuller Memorandum", and my hands are too sore to continue typing!)