Children of Madness by Jarrett Brandon Early

The Imperator of Quaan restlessly awaits the centennial arrival of the Snail-Gods to cure the Gloomtide, a shadow of melancholy blanketing the Titian Empire. But when the Supreme Helices finally make landfall, they do so out of reach of the distressed monarch, beyond a poisonous grove that separates man from messiah.

Fincher Bugg leads the Sour Flower Gang, the preeminent child harvesters of the Stenches, a town of outcasts condemned to diminished lives in toxic conditions. As Fincher and his four friends endure external abuse from outsiders, internally they also suffer, watching as their parents slowly succumb to the Maddening. Despite the solace of unbreakable friendship, life is unrelenting.

When a desperate king makes a seemingly magnanimous offer to a hopeless population, the Sour Flower Gang sets out on a harrowing expedition to find God for the very people who cast them aside.