Marshal Clay Brooks is summoned to Boise, a frontier city on the brink of prosperity-and on the edge of an unseen abyss. Its streets are busy, its people hopeful, unaware that something old and malignant has taken root beyond the firelight. When whispers of violence and vanishing souls reach him, Clay withdraws to the Dry Creek Valley in the hills above town, sensing the threat will come from the wilderness, not the streets. What he uncovers is not banditry, nor rebellion, but a creeping supernatural terror that feeds on belief, fear, and silence. Bound by orders from the Department of the Columbia, the soldiers of Fort Boise are forbidden to intervene. The law will not help him. The truth will not be believed. And the enemy does not announce itself until it is already among them.

As winter tightens its grip and night falls longer over the valley, Clay must decide what he is willing to sacrifice to stop a darkness that cannot be reasoned with-only resisted. Because some evils do not want the land. They want the soul of it.