Matthias opens Nina’s cell, and Nina briefly remembers the fear that Matthias had betrayed her, but Matthias’s actions and vow reassure Nina that Matthias has chosen her over Fjerda. Matthias tells Nina that Yul-Bayur is in the vault, and the two hurry through the Ice Court while Black Protocol bells ring, hoping to reach Kaz’s planned meeting point by the sacred ash.

At the vault, Nina disables the guard, and Matthias uses Brum’s key to open the door. Instead of Bo Yul-Bayur, Nina and Matthias find a teenage Shu boy, Kuwei, who reveals that Bo Yul-Bayur was his father and died during the earlier attempt to remove them from Ahmrat Jen. Kuwei explains that the Fjerdans have kept Kuwei alive because Kuwei helped in the lab and may be able to recreate jurda parem.

Nina considers killing Kuwei to prevent more suffering, thinking of the Grisha ruined by the drug, but Matthias reminds Nina that Kuwei is only a child and one of them. Nina spares Kuwei and asks how quickly Kuwei can destroy the lab. Kuwei reveals that Kuwei is Grisha, an Inferni, and that Bo Yul-Bayur was also Grisha; the drug was originally created as part of Bo Yul-Bayur’s effort to help Kuwei hide Kuwei’s powers.

Kuwei rigs the vault to explode while Nina insists they limit the blast because there are Grisha and others elsewhere in the treasury. Nina, Matthias, and Kuwei flee outside, but guards spot them near the maze. The lab explodes, throwing Nina to the stones and creating enough chaos for Nina to try to bluff the guards, but Lars recognizes Matthias and realizes Matthias has betrayed the drüskelle.

Drüskelle capture Nina, Matthias, and Kuwei with barbed retractable cables that prevent Nina from using her power. Lars denounces Matthias as a traitor and prepares to take them away for interrogation, but Lars suddenly bleeds and collapses. Kaz, disguised as one of the drüskelle, has infiltrated the group and taken control of the whip attached to the cables.

At the same time, the sacred ash cracks and begins to fall, revealing the black shaft beneath its roots that the drüskelle believed carried Djel’s voice. Kaz warns Nina, Matthias, and Kuwei not to trigger their baleen too soon, then jumps into the hole with Kuwei, dragging Nina and Matthias after them by the cables. The chapter ends with Nina falling into darkness, cold, and gunfire as Kaz’s escape plan begins.