Kogoro is called to meet with Toshio Higashiyama at his company building and takes Ran and Conan with him. Upon entering the building, they are asked to call his sectional number, 423. After getting in contact with him on the phone, they witness the employee Fujihiko Takahaka, fall from the building to his death.

As the police continue their investigation, they discover a plastic tea bottle filled with water in the dressing room, match cinders floating on the water, and Tetsuyama's silver-gemed ring. It is also revealed that all the suspects have been seen in the hotel after the sauna was closed disproving their previous theory.