Nina, a Grisha Heartrender, struggles throughout the novel toward two conflicting goals. On the one hand, she wants to defend her people, the magical Grisha, against the drüskelle, the Fjerdan soldiers who have solemnly vowed to destroy all Grisha. On the other hand, she wants to make peace with Matthias, the drüskelle soldier with whom she has a complicated history and a love-hate relationship. These opposing priorities create constant dilemmas for Nina when Kaz frees Matthias from prison and coerces him to join the heist. Matthias hates Nina for her perceived betrayal, which landed him in prison, whereas Nina loves Matthias but struggles to reconcile his better qualities with his blind hatred and demonization of Grisha.  

Throughout the novel, Nina remains true to her values and uses her considerable charm—magical and otherwise—to achieve both of her goals, albeit at a great personal cost. Eventually, she wins over Matthias, convincing him to renounce the drüskelle and aid her in the mission to prevent them from using jurda parem to enslave and destroy the Grisha. During the heist, she uses her powers of seduction to infiltrate the highest echelon of drüskelle society, and she employs her magical powers to heal and protect her fellow Dregs. In the end, she demonstrates remarkable courage, sacrificing herself to save the mission by taking jurda parem herself. In so doing, she acquires temporary powers that enable the gang to complete the mission and escape certain death, but she also risks the potentially fatal ravages of addiction.