There's something the matter with Ludlow, Pennsylvania. Something in the water. When Malcolm Warner first learns about the Light in the Dark, it sets in motion a ghastly, grisly crusade for the heart and soul of this tiny town that draws everyone to banks of the Mercy River, and something dreadful living in the muck and shadows. A few brave townsfolk desperately try to stem the tide of the Brethren who move inexorably to claim the town, and the world beyond it. Can anyone resist the Light in the Dark?