The work mainly revolves around Sohei Saigawa, one of the members of Saigawa's laboratory, and Moe Nishinosono, the daughter of Saigawa's mentor. Although Moe is not a member of Saigawa's laboratory, she participated in the laboratory's research trip, which was set on Himinga Island. Later, at Moe's suggestion, Saigawa and Moe went to visit the Magata Research Institute located on the island, but they found a body in the secret room there. Taking this as an opportunity, a series of murders occurred afterwards, and the two people involved worked together to solve the mysterious serial murders...