Charlie insists on one more stop before pursuing Elden: the torture chamber near Deep Maleen. There he finds Percival alive but mutilated—his hand severed. After a brief reunion, Charlie orders Jaya to escort Percival to safety for treatment. Percival warns that Elden (the Flight Killer) has gone below with four men and Petra. Leah leads Charlie, Eris, and Radar through a hidden wardrobe passage toward the Dark Well as eerie green light and taunting voices assail them.

They descend into vast, ancient tunnels where the hum of a malign power grows. Leah, remembering childhood explorations with Elden, guides them to a cathedral-like chamber with many passages. Overwhelmed, Eris flees, but later returns. Using a scrap of Petra’s green silk, Charlie has Radar track Elden’s route; they follow a steep glassy tunnel into a colossal shaft beneath an impossible sky strewn with alien stars and a towering derrick over the Dark Well.

Leah rushes down the spiral toward Elden’s palanquin. His bearers panic; one impales himself on Leah’s sword and falls; two flee, and Radar’s bite sends the third to his death. The sky brightens as the moons kiss; the derrick lifts the hatch. Elden, crowned but half-transformed into a mass of tentacles, stands at the well. Leah recognizes him, slashes open her feeding sore to speak, and calls to him. Elden hesitates, then tentacles seize Leah and Charlie; a tendril knocks away Mr. Bowditch’s pistol.

A thorned wing from the well flops onto the floor as Gogmagog begins to emerge. Leah stabs Elden in the eye; the wing wraps and hooks him, dragging Elden into the well. The monster rises further, vast eyes staring, foul wings beating. Charlie, realizing the old fairy-tale law, speaks its name—Gogmagog—over and over, forcing it back in agony. Leah commands the derrick to close the hatch, and it lowers, sealing the Dark Well.

At the palanquin, Petra erupts and bites a chunk from Charlie’s forearm; Leah recovers the dropped .45 and kills Petra with a single shot, then bandages Charlie and lights a lantern. The trio climbs out; when their light dies, the Snab arrives with swarming fireflies, guiding them back to Eris and the hidden wardrobe.

They emerge to crowds in the plaza under clearing skies and returning sunlight. Supported by Leah and Eris, Charlie announces Elden’s death and the sealing of the Dark Well, then hails Leah of the Gallien as queen. As the grayfolk kneel and cheer, Charlie finally collapses.