The Detective Boys hear a rumor from a classmate where a warehouse one second, was filled with treasure and how they all disappeared the next. Before heading to the warehouse to investigate, the Detective Boys drop by Conan's house where they run into an unknown person unbeknownst to Conan. During the warehouse investigation, Conan notices that there were recently made footprints from an adult even though the warehouse has been locked up for years and that the footprints lead up to an abacus with an odd number of beads. Conan decides to look through the warehouse by climbing a tree and…