Vow of Thieves (2019) is the second installment in the Dance of Thieves duology by New York Times bestselling author Mary E. Pearson. It is Pearson’s sixth book set in the Remnant Universe, which is a medieval-styled world built on the ruins of the modern United States. This young adult fantasy novel continues the saga of Kazi and Jase from book one, Dance of Thieves, as they navigate betrayal, romance, and family amidst the turmoil of their world.

This guide references the 2019 Henry Holt and Co. eBook edition.

Content Warning: The source material features depictions of sexual assault (coerced kissing), violence, and warfare, including torture and executions. These are handled with sensitivity toward the target audience of young adult readers.

Plot Summary

Kazi, an ambassador for the Vendan queen, and her husband, Jase Ballenger, travel together to the fortress of Tor’s Watch to help ensure a smooth transition as Tor’s Watch and the nearby town of Hell’s Mouth are joining the kingdom of Venda. Jase is the leader of Tor’s Watch. Kazi is anxious about meeting the Ballenger family, wondering if they will accept her. Upon arrival, they are shocked to find Tor’s Watch severely damaged. Suddenly, the invaders attack them. They severely injure Jase, but Kazi manages to help him escape. The attackers wound and capture Kazi, throwing her in a cell.

In captivity, Kazi battles delirium while slowly healing. She eventually learns that General Banques and King Montegue of Eislandia have taken over Hell’s Mouth, claiming that they are protecting the local populace from the Ballengers’ extortionary tactics. When Banques meets Kazi, he threatens to hang her for conspiring with the Ballengers. Just then, Paxton, one of Jase’s cousins who has joined King Montegue’s forces, brings news that Jase is dead; as proof, he shows a mangled hand wearing Jase’s signet ring. Kazi is devastated.

King Montegue meets her soon after, and he tries to persuade her to announce that Jase was executed in Venda; he says this will provide closure to the locals rather than telling them the truth. When Kazi refuses, Montegue blackmails her—he has captured the two youngest Ballenger children and uses them as leverage to convince Kazi to do his bidding. He escorts her to the plaza, where Kazi reads a prepared statement declaring Jase was executed in Venda and that Montegue is the rightful ruler. Meanwhile, unknown to Kazi, Jase has been rescued by Vendan settlers who are hiding him and tending to his wounds.

King Montegue celebrates Kazi’s announcement with a feast, probing her about the Ballenger vault. He also flirts with her. Kazi deflects his advances and questions. He succeeds in forcing Kazi to declare that she will stay in Hell’s Mouth to help his cause. When Kazi gets a chance to speak to the two youngest Ballenger children, they tell her about their hatred for Montegue, and Kazi promises to help them escape as soon as she can figure out how.

After Jase has healed from his injuries, he disguises himself and plans to find Kazi. Wren and Synové, Kazi’s closest friends, join him, learning of Kazi’s imprisonment. Kazi gets into a fight with Jase’s cousin, Paxton, calling him a traitor; however, Paxton reveals that his allegiance to Montegue is only a ruse to protect the Ballengers. Kazi and Paxton plot together to free the two Ballenger children who are being held by Montegue.

Meanwhile, as Jase struggles to understand Montegue’s takeover of Hell’s Mouth, he meets Aleski, a former employee, who claims Kazi is working with Montegue. Jase insists she is not.

Montegue wants Kazi to search for the scholar Phineas’s papers, which outline his formula for “stardust,” a rare element that provides unfathomable power. He shows Kazi a vial of this stardust and says that the Ballengers had the papers. Kazi convinces Montegue to return to Tor’s Watch with the two Ballenger children so they can search for Phineas’s papers.

During their journey to Tor’s Watch, Kazi kills a guard and hides the two Ballenger children in an empty crypt. When Montegue discovers that the children are missing, he turns on Kazi, immediately suspecting her of this betrayal; Kazi stabs him and flees, taking his vial of stardust with her. As she runs, she hides the stardust and then unexpectedly encounters Ballenger clan members. They think she is a traitor, so they push her into a snare, trapping her for Montegue’s approaching soldiers.

As Jase, Synové, and Wren reach the Ballenger family vault’s secret entrance, Paxton appears, explaining that he is searching for Kazi. He tells them she succeeded in saving the two Ballenger children. When Jase reunites with the rest of his family, he is shocked and disappointed to discover that they trapped Kazi. He insists his family help him rescue Kazi from Montegue.

Meanwhile, soldiers capture Kazi and bind her. Montegue arrives, scarred from Kazi’s knife, and interrogates her about the whereabouts of the vial and the children. Kazi refuses to reveal any information, and he decides to have her executed. The Ballengers work together to save her, and Jase rushes her to a healer. When she awakens in the vault, confused but safe, the Ballengers welcome her warmly.

The Ballengers plan to steal Montegue’s munitions. As constant patrols hinder their food supply, Montegue’s troops blast through the mountain, toward the vault. Kazi realizes Montegue’s munitions are below Tor’s Watch and volunteers to search. Upon arriving at Tor’s Watch, Kazi distracts guards while Jase eliminates them. They discover a room filled with munitions, soak it in kerosene, and ignite it. They narrowly escape the explosion, returning to the vault as it shakes but holds firm.

Jase decides to attack Hell’s Mouth before Montegue’s forces regroup. The town has been destroyed by Montegue’s mercenaries, who have ransacked it. The Ballengers enter the town, engaging in skirmishes. Jase fights Montegue in a sword duel, defeating him, and the Ballengers reclaim the town. Kazi and Jase hold a marriage celebration and they rebuild Tor’s Watch. A crow finds the hidden vial of stardust and accidentally scatters it over the land.