Kogoro, Ran, and Conan attend a tea meeting at the Aonogi family house in place of Sonoko and her father. Behind the house is a pond that changes colors. When the group crosses the pond to the tearoom on the other side, the headmaster is found hung!

The Detective Boys are out looking for mushrooms in the forest. Genta sees good mushrooms on the other side of a fence, which marks the animal hunting area. On the hunting side, a man is found dead.