Krantzberg syndrome haunts me because it’s a personal bête noire. Magic is a side effect of certain classes of mathematics, notably theorem proving. Sensible magicians—like me—use computers. But if you’re smart and agile you can perform some types of invocation in your head. The trouble is, just as our symbol manipulating machines attract the attention of extradimensional agencies (demons, you might say), so do such DIY invocations. If you perform ritual magic regularly, some of the things you invoke will chew microscopic holes in your gray matter. At first it’s not too bad, but the dizziness, numbness and tingling in the periphery, memory problems, and lack of coordination are irreversible and frequently progressive. The end result, Krantzberg syndrome, bears a rather unpleasant resemblance to Creutzfeldt-Jakob disease—not to mention that other happy fun prion disease, Kuru (which you can only contract by eating the brains of someone who had the condition).

Krantzberg syndrome is what people like me die of if the monsters don’t get us first.

“There’s a blood test for new variant CJD”—Mad Cow Disease, to you—“so what I’m going to look for is cases of CJD diagnosed at post-mortem that test negative for nvCJD. Testing CJD cases for nvCJD is routine and gets reported to the Core Data Service as part of the program for tracking Mad Cow Disease; I’m going to see if I can pull out a geographical plot,” I explain.

“What do you expect it to tell you?” Andy leans forward.

“It’s too early to tell. For all I know, I’m going to draw a negative. Actually, I hope to draw a negative—finding a Krantzberg syndrome hotspot in the community wouldn’t be good.” (This is an understatement, to say the least: depending on how big a hotspot and where it was located, it could range in severity from a rain of boiling frogs to the End Of The World. File under Apocalypses and just hope it doesn’t happen.) “It’s got to be done. The vampire/werewolf cross-check is just a control, really.” (Which is what Mo latched onto a month ago and wouldn’t let me finish explaining, dammit.)

“How long do you think it’ll take to get results?” he asks.

“Ah, well, that’s a good question.” I smirk unashamedly and fondle the shiny new smart card reader next to my keyboard. “Shall we see?”

“What, here and now?”

“When else?”

I start mousing around.

Now pay attention: