To save her terminally ill grandmother, Evelyn sneaks into the ancient castle of vampire nobleman Carlos to steal a blood crystal, but is caught on the spot. Carlos imprisons her in a secret chamber and demands the blood crystal in exchange for her grandmother's treatment, draining her blood weekly. As escape attempts and relentless pursuit unfold, their relationship spirals out of control amid power struggles and resistance. Betrayed by her fiancée Celine and hunted by the Vampire Hunters' Guild, Evelyn finds herself trapped in escalating danger. Amid the chaos, Carlos uncovers the truth behind his mother’s death three centuries ago—the killer was none other than Celine’s father, Marcus. Carlos takes revenge with his own hands. Celine sets a deadly trap meant to destroy them both, but Carlos shields Evelyn with his body, taking fatal wounds. Using her pure blood, Evelyn saves him, binding them together through a sacred blood oath.
