Darkly the Thunder — William W. Johnstone

THE ROOT OF EVIL

The ominous rumblings of thunder -- dark thunder, was how retired head of police Al Watt thought of it -- had started thirty years before on the night that Sand was killed. A good man, that Sand, and when he died, the forces of darkness had taken root in Willowdale, Colorado. Now the isolated little town, nestled in the Rockies, was about to give birth to an evil beyond comprehension, beyond imagining... a reign of terror so insatiable that Al Watt could do nothing to stop it.

CHILD PRODIGY

Something bad was going to happen. Eleven-year-old Howie Ingram could feel it in his bones. Of course no one ever listened to Howie Ingram, the twerp. All they did was make fun of him for being so smart he was already taking high school and college courses. Howie tried not to care. Except now he really needed someone to listen to him when he told them about the townspeople turning into zombies and the strange noises coming in over the air waves. And the distant sound of thunder. He and his computer didn't stand much of a chance, alone, against a force as powerful and primitive as Satan himself...