Deep in the Appalachian Mountains of the US, young witch Elena Vale was framed by her stepsister Vivian five years ago and strayed into the vampire castle Nightfall Keep, where she entered into an out-of-control Blood Moon Pact with vampire lord Adrian Blackthorne on the night of a lunar eclipse. After that night, Elena became pregnant with six half-vampire infants.
Five years later, the bloodline curse afflicting the six children began to intensify. Oliver, the intelligent and composed eldest child, sealed himself in a small black wooden coffin gift box to save his younger siblings, voluntarily delivered it to the vampire castle, and shouted "Daddy" right in front of the indifferent lord Adrian.
Adrian is shocked to discover that he actually has children, and Elena has tracked him to the castle, desperate to take the kids away. What she fears is not acknowledging the parent-child bond, but that the ancient vampire clan will seize the six children. As Finn, Hazel, Theo, Jasper and Milo are exposed one after another, Adrian realizes he doesn't have just one child, but six half-blood heirs.
Meanwhile, Elena's stepsister Vivian has been impersonating the Eclipse Bride from five years ago, scheming to become the mistress of Nightfall Keep. Adrian's aunt Morgana has long been aware of the six children; she intends to use Vivian to replace Elena, seize the children's maternal status, and gain control over the inheritance rights of the ancient Blackthorne clan.
