For three hundred years the Hollow Moon has turned, its vast brass heart spinning the aetheric currents that hold the sky-cities aloft. Then the grinding begins -- slow at first, one missed beat in ten thousand, then ten in a hundred -- and the cities begin to list.
Sable is sixteen, an orphan engine-tender in the lower warrens of Crestfall, a city already tilting four degrees east. She knows the sound of a gear that is giving up. She also knows that the Ascension Authority's last repair mission is a lie, because she has read the manifest, and the cargo listed is not tools.
So she stows away aboard the Verity's Climb, the final ship permitted to reach the Moon's core before the approach-lanes are sealed forever. What she finds on the other side of the sky will force her to choose between the truth and the last chance to save everyone she has ever known
