Sold to the vampire royal family by his stepfather to repay a debt, young human Evan believes he is nothing more than property offered to the Night King, Adrian Blackthorne. But the moment Adrian tastes his blood, a heart that has been silent for a century begins to beat again. Evan is revealed to carry the legendary Moonborn bloodline, capable of awakening the true Night King and changing the future of vampire society. Pulled from the status of blood servant into the center of royal power, Evan faces noble humiliation, Adrian's old engagement, Council trials, Cassandra's schemes, and Lucien's attempt to seize the throne. Even as Adrian repeatedly breaks ancient rules to protect him, Evan struggles to believe he is loved for himself rather than for his blood. Their bond deepens when Evan learns he is carrying Adrian's heir, Aria, a child born with both royal vampire and Moonborn blood. After Aria's birth makes the family the target of a larger power struggle, Evan and Adrian fight back together. Lucien falls, Cassandra and Marcus are banished, and the couple finally completes a public wedding before vampires and human delegates alike. Standing beside Evan and their daughter at the throne, Adrian abolishes the buying of human blood servants and declares that Moonborns will never again be used as sacrifices, turning their forbidden bond into a new law for the night.
