Conan and his friends come to a lodge and fossil museum in Gunma to go on a fossil finding trip. Journalist Miyashita Umika also arrives at the lodge. She explains that she has come to write a story on the rare moon`s droppings fossil that was discovered in the town. Museum owner Ogami and village mayor Nakatani are planning to make the fossil the town`s village in order to promote it, but Umika mutters that she hopes it doesn`t become a negative symbol. Later, Ogami is interrupted while trying to tell something to Umika, and his dead body is discovered in the bathroom...