Milo is invited to go camping with eight other people during summer vacation, but he is worried when he hears that the place is where a mass murder took place a long time ago. When he arrives at the villa and walks along the lakeside with Drill, whom he befriended along the way, a mysterious old woman appears and tells him, "If you want to live, leave...". What awaits them after that are dismembered corpses stuffed into flowerpots, members being killed and maimed by a strange monster, massacres repeated over and over again in town, the prophecy of the Topi tribe who have survived, the night that never ends, the "test moon", and the magic of the "catastrophe rock". Against the Topi tribe's prophecy of genocide, what will be the fate of Milo and his friends as they fight against the monster, against the catastrophe brought about by humanity's primitive desires, fears, and emotions? The breathtaking development and the shocking ending will hit you. In addition to the main story, three prototype chapters are also included!