The Oath (Abridged) - Frank Peretti

Something sinister is at work in Hyde River, an isolated mining town in the mountains of the Pacific Northwest. Something evil. Under the cover of darkness, a predator strikes without warning--taking life in the most chilling and savage fashion. The community of Hyde River watches in terror as residents suddenly vanish. Yet the more locals are pressed for information, the more they close ranks, sworn to secrecy by their forefathers' hidden sins. Only when Hyde River's secrets are exposed is the true extent of the danger fully revealed. What the town discovers is something far more deadly than anything they'd imagined. Something that doesn't just stalk its victims, but has the power to turn hearts black with decay as it slowly fills their souls with darkness.