A large group of reporters have gathered in front of the Kudo family home. Everyone online is talking about how Shinichi solved the Fighting Red Tengu murder case. Conan decides to hide in Agasa's home until the commotion blows over. Haibara, Genta, Ayumi, and Mitsuhiko are asked by their homeroom teacher Kobayashi to visit Higashio Maria's home after school. Maria should have been at school that day, but she never showed up. Believing Maria most likely went to look for the treasure hidden by her late grandmother, Haibara and friends begin deciphering the treasure hunt clues, but...