The vampire Vilande family sacrifices a human bride every century to stabilize the seal. Ancient king Lucius endures power backlash and awaits the offering. Orphan Eileen is sent to the castle as a substitute tribute. Her blood sustains the seal and heals Lucius. Bound by contract, they fall for each other. Vampire Isolde conspires with traitors against them. Eileen awakens her guardian bloodline. They crush the plot, escape sacrificial fate, break vampire taboos and redeem each other.