The duke’s illegitimate daughter, Ivy, is forced to marry the Blood King, Carlisle, in place of her younger sister, Lydia. To survive, she forms a blood pact with Carlisle, triggering a shared connection that binds their lives together. As they grow closer, their initial distrust and hostility gradually turn into mutual affection and protection. Selena, a noblewoman of the Blood Clan who deeply loves Carlisle, reveals the secret of their blood pact out of jealousy and helps her half-brother, Elias, seize the throne, triggering the backlash of the blood pact. At the brink of death, Carlisle bears the cost of breaking the pact and gives Ivy her freedom. But Ivy chooses to follow her heart and return to his side.
