Luna, a human orphan, was kept for 18 years as the personal blood supply for vampire brothers Victor, Kyle and Lorne. Weakened by constant blood draws, she escapes back to the human world. The three vampires dismiss her at first, but soon collapse from bloodlust and regret, becoming her secret protectors. When old vampire factions kidnap Luna for a bloodline trial, she stands up to defend them. A serum project ends their need for her blood. At last, Luna chooses to build a new life with the brothers, who now treasure her as a person, not food.