To save her mother, the fallen heiress Elena signs a contract to marry Vincent, a seemingly wealthy but actually comatose man. Upon entering the castle, she discovers her husband is actually a sleeping pure-blooded vampire king. Using her exceptional business acumen, she rises to power in the business world, reclaims her family fortune, and gradually awakens Vincent. Their relationship evolves from a contractual marriage to a bond of life and death, as they join forces to eliminate internal family enemies and thwart conspiracies. Ultimately, Elena willingly drinks pure blood, transforming herself into a vampire queen, and together with Vincent, they forge an eternal legend in the darkness and on Wall Street.