Thousands of years of knowledge

"No," I said. "Nicodemus also had these...call them guard dogs, I guess. Except that they weren't dogs. I don't know what they were, but they were ugly and ran fast and had big teeth. But all of that isn't what makes them dangerous."
"No?" Thomas said. "Then what is?"
"The Fallen," I replied.
The room fell silent.
"They're beings older than time who have spent two thousand years learning the ins and outs of the mortal world and the mortal mind," I said quietly. "They understand things we literally could not begin to grasp. They've seen every trick, learned every move, and they're riding shotgun for each coin holder-if they aren't in the driver's seat already. Every one of them has a perfect memory, a library of information at his immediate disposal, and a schemer that makes Cardinal Richelieu look like Mother Teresa hanging around in his brain as an adviser."
Thomas stared at me very hard for a moment, frowning. I tried to ignore him.
Murphy shook her head. "Let's sum up: an unknown number of enemies with unknown capabilities, supported by a gang of madmen, packs of attack animals, and superhumanly intelligent pocket change." She gave me a look. "It's sort of tough to plan for that, given how much we don't know."


Small Favor Chapter 18, Page 148