Cassian accompanies Feyre to the Prison, deep inside a mountain on an island off the western coast. He questions whether it’s possible to control the Bone Carver, let alone free him. Feyre admits the plan isn’t fully formed, but Cassian counters that war requires “only picking between the bad [ideas]” (234).

At the Bone Carver’s cell, the ancient god appears to Feyre as her future son with Rhysand. The Bone Carver smells his sister’s scent on Feyre; his sister, Stryga, is the Weaver of the Wood, an ancient terror whom Feyre stole from as a training exercise at Rhysand’s request. The Bone Carver repeats Nesta’s name, cryptically indicating that she took something from the Cauldron. Feyre insists they are there to make a deal that will send him back to his original world.

The Bone Carver prefers to remain in the Prison; he fears Stryga and their older brother, another death-god named Koschei. Long ago, he allowed himself to be captured in order to hide from them. Cassian declares they should go; they must travel to the Hewn City that night. Hearing this, the Bone Carver tells Feyre he will take her deal if she brings him Keir’s Ouroboros mirror, which once belonged to the Weaver.