It's 1943 and the Rosatis, an Italian family of noble lineage, believe that the walls of their ancient villa will keep them safe from the war raging across Europe. Twelve years later, Serafina Bettini, an investigator with the Florence police department, is assigned to a gruesome case --- a serial killer targeting the Rosatis, murdering the remnants of the family one-by-one in cold blood. She finds herself digging into a past that involves both the victims and her own tragic history.

Professor David Ullman doesn’t believe in demons, though his extensive knowledge of the literature of the demonic --- especially Milton’s PARADISE LOST --- has won him wide acclaim. When he is lured to Venice on a mysterious journey, he loses his 12-year-old daughter to an ancient evil that will force him to come face to face with all he knows about the underworld and the faith required to defeat it.