Twin sisters Cordelia and Miranda know nothing about the mother who abandoned them soon after their birth. When their father dies and Miranda insists on tracking down their mother, the sisters discover the dark heritage in their bloodline. Their mother is a vampire, and from her they have inherited certain psychic powers. When Miranda disappears, Cordelia has to seek help from Karl, an old family friend. Unknown to her, Karl, a vampire, has been watching over her family for generations. He loved a distant ancestor of theirs, and Cordelia bears a compelling resemblance to his lost love.

A would-be vampire slayer has kidnapped Miranda to strike at Karl through the family he has vowed to protect. At the same time, their mother’s brother, who scorns humanity as an inferior species, has his own agenda for his half-human, half-vampire nieces. Karl and Cordelia must join forces to save her sister. In the process, they form a blood bond that leads to deeper intimacy than either one expected. Cordelia struggles with both her dawning love for Karl and the exhilaration and terror of embracing her inhuman side.