After her father's sudden death, seventeen-year-old Melissa Marchellis moves onto the former estate of nineteenth century composer and pianist John Simons, where a mysterious mist stalks her, ghostly piano music plays in her bedroom, and visions of John Simons' young wife Bryony, who died in childbirth, invade her dreams. Those dreams, Melissa discovers, are simply a distraction for the midnight feedings of John Simons, now a vampire. So, John proposes a trade: Melissa may visit the past as Bryony in exchange for minute samples of her blood to neutralize his vampire state. For a time, Melissa happily seesaws between her adolescent routine of school, slumber parties, and cute boys to dancing at balls, attending formal dinner parties, and hosting garden fetes. But fantasy and reality blur when her eccentric, middle-aged English teacher penetrates her dreams as Melissa's dashing, young vampire chaperone; her brother Brian adopts a peculiar stray cat after a friend disappears in a midnight exploration of the dilapidated mansion; and another girl with a similar vampire pact is gruesomely murdered. Caught between the danger of her agreement and her escalating infatuation with John Simons, Melissa contends with other vampires and their agendas, while struggling with her feelings for an undead musician.