This is a story of a man, his daughter and something very demonic, and unnamed. The main character, Professor David Ullman, is an expert on Milton's Paradise Lost, and has a somewhat tongue-in-cheek reputation as a demonologist because of it. His marriage has just dissolved, and he's left with his young and very withdrawn daughter. So it seems fortuitous when a visitor comes to his office and asks him to travel to Venice to "witness a phenomenon"--bringing his daughter was fine and the money offered staggering. But the phenomenon turned out to be beyond hellish, and was now attached to him and his daughter. The professor is pushed into more and more terrifying situations in order to get them free, all the while appearing a madman to everyone else around him. This book is creepy, breath-stealing and pretty much impossible to put down. It's not for the faint of heart, but if you are up to it, it's a riveting read.