Cast away to the vampire‑ruled night castle as a living blood sacrifice, a bold nineteen‑year‑old human noble strikes a risky three‑month wager with the arrogant ancient vampire prince. If she can seize back her stolen birthright and claim her family’s domain, she shall gain total freedom. Returning to human lands, she dismantles her scheming fake‑sister and cruel father, rising to become the youngest human overlord. Though the cold‑hearted prince once views her merely as precious blood supply, he gradually falls for her fearless spirit. When ferocious werewolf forces launch deadly hunts, the pair endure brutal battles, betrayal and mortal wounds. He performs forbidden eternal turning to save her life, and the two powerful souls stand side‑by‑side, building a new order and ruling the northern realm as equal dual monarchs.
