Sarah Engelmann, the teenage daughter of a rabbi, begins to have unsettling dreams and also hears the sound of a horn being blown, even when awake. These strange dreams take on new and even more unsettling meaning when Sarah and her friends - twins Anne and Sam Williams, and their new Greek classmate, Alex - discover the body of a young man, whose corpse bears what appear to be what Sarah discerns as evidence of some kind of ritual. She turns out to be correct, when they see the dead boy again after his funeral. Alex reveals himself to have quite a knowledge of the undead, and the foursome become determined to find and destroy the vampire who turned him (after dealing with him first, of course).
The plot thickens and faith is tested as they find that they have gotten themselves involved in something much more complicated than simply the arrival of a centuries-old vampire: he is in league with gods of the Egyptian pantheon, who want the Archangel Gabriel's trumpet, and a powerful warlock with a demon lover who has the ability to travel between celestial realms. Deep secrets are unveiled and Sarah becomes attuned to her faith in ways she never knew possible, and with the help of her father, she uses what she's learned to help her friends in the battle they are now desperate to fight. The stakes have become very high, and Sarah's dreams are becoming more and more disturbing. Will they be able to stop the forces they have pitted themselves against? Are they even ready to pay what it might cost them to win?