The Rhesus Chart by Charles Stross

Perhaps it would be inevitable that the Laundry would have to deal with vampires, eventually. Or would they? After all, everyone knows that vampires don't exist...and they seem particularly sure of it in that bureaucratic branch of the British civil service that deals with gibbering horrors and threats from beyond.

Seem a bit fishy? Well, it will to Bob, too. If you've read any of the Laundry books before, then of course you'll know Bob. I have read them all out of sequence, but this one is a little further than I'd read before, and, I think, the book right after the last Laundry book I got, putting me more or less on track? The big disaster where Cthulhu takes over the world is still on the horizon, and in the meantime, the Laundry is doing everything it can to keep that day at least a little further off. Including sending Bob's wife, Mo, on increasingly taxing missions with her magic violin that does nasty things.

Meanwhile, Bob is still sort of in the Laundry, and sort of in the next level up, which does more deniable things, and which the average Laundry-dweller knows nothing of. I was delighted to see that the reverend character, one of Bob and Mo's friends that Bob got unfortunately embroiled in the occult in the last book, is back. As are some of Bob's old red-tape mates from the bureaucracy. And, of course, the security zombies.

Stross also brings back a character from near the beginning of the series, Bob's ex-girlfriend, Mhari, now working for a banking/investment research firm. As is often the case in this series, young people with a lot of computer knowledge and little wisdom can use computing power in ways that have unfortunate outcomes - in this case, leaving one, and then many, of their research team with what is eventually dubbed PHANG syndrome, by someone who obviously really, really needs the acronym to make a vampire joke.

They can be burned by sunlight, influence impressionable minds, and drinking human blood brings on something like an orgasm - oh, but it turns out it's because you've set up a link to an extraterrestrial creature which has established a branch office in your mind and uses the blood to suck the victim's brain dry, while keeping its host happy. That part...not so great. As is said repeatedly, once most people have figured it out, they've done the decent thing. This inadvertently creates a natural selection where few remaining vampires who've lived centuries are psychopaths.

Bob, in his off hours, is doing an extra-work project, because they're all required to spend 10% of their working time on their own projects without actually being given 10% of their time to do so. In so doing, he accidentally discovers the start of the investment thinktank vampire incursion on London, and marshals all his resources - only to find out that Mhari is a few steps ahead of him.

Added in to the mix of new vampires and old vampires is a wonderful but brief jaunt into what a 1950s public occult awareness campaign might have looked like - the reverend, whose name I still can't remember, is given the job of updating it for a digital age.

As is always the case with this series, I had a lot of fun reading the book. I can't say it's the deepest thing ever, but they're always worth some time, and provoke a fair number of wry grins. I also particularly liked the appearance of a demanding cat. And the take on vampires was interesting - I liked the explanation for why vampires are evil killers quite a lot.