Newspaper writer, family man, and reluctant hero Zack Walker has stumbled onto some dicey stories before, but nothing like what he’s about to uncover when a mutilated corpse is found at his father’s lakeside fishing camp. As always, Zack fears the worst. And this time, his paranoid worldview is dead-on.

While the locals attribute the death to a bear attack, Zack suspects something far more ominous—a predator whose weapons include arson, assault, and enough wacko beliefs to fuel a dozen hate groups. Then another body is discovered and a large supply of fertilizer goes missing, evoking memories of the Oklahoma City bombing. But it’s when he learns that his neighbor is a classic Lone Wolf— FBI parlance for a solo fanatic hell-bent on using high body counts to make political statements—that Zack realizes the idyllic town of his childhood is under siege. The fuse is lit to a catastrophe of unimaginable terror. And with time running out, Zack must face off with a madman.