A Colorado mountaintop has been transformed into a self-sustaining utopia by a man who claims to be the second son of God. He has built a perfect city—a sanctuary for his most devoted followers. Heaven on earth. Holy Mountain. But the children trapped inside the high walls of Holy Mountain know the truth: this isn’t heaven, it’s hell. Cameron Rollins, a fourteen-year-old boy who grew up in the arms of the cult, sneaks out at night, climbs the wall, and calls for help. When he is captured, he knows the punishment will be severe. It wasn’t his first offense, and it won’t be his last. But this time, someone has heard his cry. Eric Larson has been tasked with retrieving a young girl trapped inside Holy Mountain. And when he records a video of Cameron crying for help, he plans to use the evidence to stop the depraved cultists once and for all. But Holy Mountain’s dark influence extends farther than he thought possible, and his hopes are dashed by a corrupt judicial system. The law has failed to protect the children trapped inside Holy Mountain, so Eric decides to take matters into his own hands. He will enter the city and gather undeniable proof of the wickedness inside. And if he fails, he will call upon the most dangerous vigilante the world has ever seen—a genetically enhanced assassin known as “The Nightmare.”