" Because, you see, everything you know about the way this universe works is correct—except for the little problem that this isn’t the only universe we have to worry about. Information can leak between one universe and another. And in a vanishingly small number of the other universes there are things that listen, and talk back—see Al-Hazred, Nietzsche, Lovecraft, Poe, et cetera. The many-angled ones, as they say, live at the bottom of the Mandelbrot set, except when a suitable incantation in the platonic realm of mathematics—computerised or otherwise—draws them forth. (And you thought running that fractal screen-saver was good for your computer?) "

― Charles Stross , The Atrocity Archives (Laundry Files, #1)