Caleb Riker has concocted a plan. He's going to hunt down and kill the men who murdered his wife and unborn child. As he sets out to take justice into his own hands, an unlikely run-in with a widow named Kate Lawrence sets him on a different course that will change his life forever. The two discover that they are being hunted by dark forces that leave a trail of bodies and catastrophe in their wake, forces that use human beings as hosts and feed on destruction. Caleb and Kate are soon joined by a teenage girl on the run who has some insight as to what they're up against. As the three begin to realize the divine circumstances that have brought them all together, they discover that their survival does not depend on defeating the darkness that hunts them but on facing the darkness that's within them.