Ella Astor is the eldest daughter of the noble Astor family, but she's looked down upon because her blood is considered 'impure.' Even her fiancé, who seems to genuinely love her, only wants to use her as a sacrifice to save Lina. To escape this fate, Ella voluntarily marries her stepsister's blind, useless husband, Cyrus. As she finds warmth in her new family, genuinely connects with her husband, and becomes pregnant, her former fiancé Cain goes mad with regret—turns out Ella was the lifesaver he had mistaken for someone else all these years. Facing Cain's relentless attempts to win her back, Ella teams up with Cyrus to fight back and finally break free from the toxic bond.