Cora, an assassin controlled by Lord Falkner with poison, is ordered to kill the Crown Prince. She encounters Prince Regent Pierce, commanded to kill him. Cora disguises as "Seventeen," infiltrating Pierce's manor as his bodyguard. Suspicious Pierce tests her, but Cora protects him, developing feelings. She steals the antidote, kills Lord Falkner with Pierce's support, becoming new master. They trust each other. Zane Hale, who massacred the Pierce family, returns.
