Roman follows Val deeper through the under realm, passing a rune-carved door that opens with one of the magical keys. The air grows foul with sulfur and decay, and Roman fears Dacre may have tricked him into a death march. Instead, the passage opens onto a vast subterranean landscape of steaming yellow pools, where Val leads him to a saddled eithral waiting in the heat.

Although Roman is terrified to mount the same kind of creature that has brought so much destruction, he forces himself into the saddle because flying is his only hope of reaching Oath quickly. As Val prepares the eithral for takeoff, Roman remembers Iris and steadies himself with the thought of her. He realizes the beasts are controlled by music when Val uses a flute to command the eithral into flight.

During the journey, Roman studies the under realm and notices bones, chains, and rising vents of steam that suggest hidden exits to the world above. He keeps quiet, but his thoughts turn to Dacre's methods: using eithrals to bomb civilians, spread fear, recover soldiers, and then heal and manipulate them into loyalty. Roman concludes that Dacre must retain some way of directing the creatures even in the surface world, which may matter in the coming conflict.

When Val signals the eithral to land with a different sequence of notes, Roman survives the descent and follows him through more passages choked with briars, amethysts, bones, and darkness. Val confirms they are beneath Oath and warns Roman to speak carefully once he returns above. He instructs Roman to change clothes, meet Iris at Gould's Café, reveal little, and return by dawn the next day.

Val leaves Roman at a crystal-marked passage leading to the doorway. Alone, Roman climbs toward the surface as the air changes from the corruption of Dacre's realm to the familiar scents of home. He recognizes he is passing back through the hidden threshold connected to the Kitt Estate, opens the door, and steps into Oath at dawn.