Conan, Ayumi, Mitsuhiko, Genta, and Ai go to the Beika Department Store with Professor Agasa. During their visit, head chef Hosogoe of the restaurant on the top floor is stabbed by a customer near the stairs. Inspector Megure questions Genta, Ayumi, and Mitsuhiko who all saw the culprit, but their testimonies are all over the place. Together the Detective Boys visit the various floors to determine the why the kids seemed to have seen different culprits.