Gillian, a vampire-human hybrid in the throes of adolescence, panics at the unfamiliar urges and powers surging through her. Overwhelmed, she runs to the half-human father she has never known. Psychiatrist Roger Darvell has come to terms with his vampire half and built a good life, with a satisfying career and his human partner, Dr. Britt Loren, who is also his lover. Gillian's sudden appearance out of a December night throws him into turmoil. Can he teach her how to live as an ethical vampire without violating either side of her nature?

Before they have much time to learn to trust each other, a specialist in folklore kidnaps Gillian to study her. She is soon rescued, not by Roger, but by Camille, a vampire woman determined to avenge her brother, whom Roger killed in self-defense thirteen years earlier. Camille's wild, fierce lifestyle proves seductive to Gillian. Can she resist Camille's attempt to make her a "real" vampire, one who treats ordinary mortals as mere prey? Can Roger save Gillian before her human side becomes completely submerged in lust for the kill?