This is Bob speaking, in his capacity as your humble narrator. It’s really a bad sign when you begin talking about yourself in the second person, isn’t it? But I’m afraid I need to break in at this point and disrupt the continuity of my narrative by explaining some uncomfortable truths that only really became clear to me a few weeks after the dust settled from the events described in the RHESUS POSITIVE EPSILON file, which is to say, this document.

Luckily we live in the age of the word processor, which makes it trivially easy for me to go back and insert additional material that I have determined is not classified above your level (if you’re reading this without scorching your eyebrows off) and that you will need to be aware of in order to make sense of this utter clusterfuck. And you really do need to understand what went wrong in RHESUS POSITIVE EPSILON, if only to ensure that it doesn’t happen to you.

So wake up and pay attention now:

• • •

THE FIRST LAW OF VAMPIRISM IS THAT EVERYBODY KNOWS vampires don’t exist.

It therefore follows that anyone who realizes that vampires exist is either a vampire, or dead. (Or is a member of staff with RHESUS POSITIVE EPSILON clearance, but that’s another matter.)

Let me rewind:

Forget Dracula. Forget Anita Blake and Sookie Stackhouse and Varney the Vampire and Lestat and, oh, everything you think you know about vampires.

(Except for Desmodus rotundus and Vampyroteuthis infernalis and Goldman Sachs—they’re all real.)

Almost everything in the pop culture lexicon of vampirism is basically fiction—and fiction is the art of telling entertaining lies for money. Whereas what we’re discussing here is something else. Here in the real world of applied computational demonology and undead alien squid-gods without investment portfolios, we’re totally down with walking corpses. (If you don’t believe me, go argue the case with the Night Shift.) But vampires in the fictional mode—intelligent super-strong blood-sucking walking corpses who hang out in goth nightclubs and look incredibly sexy—don’t exist.

Am I shattering your illusions yet?

Having said that much, what we do in the Laundry centers on the practice of setting up a sympathetic link between complex computational systems in this universe and another elsewhere in the multiverse, mediated via the platonic realm of pure mathematics. We invite useful entities to poke their pseudopodia through a hole in reality, then we grab them and set them to work.

Now, vampires: