It is a “novel” written about a small rural community town and explains in a very graphic manner the invisible influence and interaction of angels, demons, prayer and spiritual warfare for control of the minds of the citizens of this small community town. It was a test case away from the limelight of the general public to introduce New Age and Eastern spiritual practices into the schools and universities to ultimately redefine society.
Reference: https://www.growingdeepandstrong.com/this-present-darkness-by-frank-peretti/