Professor David Ullman is among the world's leading authorities on Christian religion and myth. Not that he's a believer. He sees what he teaches as nothing more than entrenched fiction — the things that go bump in the mind. It's why when he's offered a trip to Venice to be a consultant on a case study based on his expertise as a demonologist he accepts, seeing it as a free vacation for his teenage daughter and himself. But what he witnesses in an attic room at an address amidst the decadent splendour of the old city will change what he believes forever. Terrified, David races back to his hotel. But now he has the unshakable feeling that he is no longer alone. And that the voice that passes from his daughter's lips before she jumps from the hotel's roof belongs to a being he has long studied, but until now never thought could ever be real...