Conan and Ran are on a train and are confronted by a pickpocket but is saved by an elderly man named Tokuma Norizuki. As the train passes Sugamo Station, they notice the police investigating something under the railway. Conan and Ran discover that a man named Kanemura, a local conartist, was killed by a head injury. Norizuki claims he witnessed Kanemura's boss, Takehiko Kiriya, committed the murder. Kiriya said he was called to the crime scene by Kanemura's friend and proclaims he is not the culprit. Conan asks Takagi to investigate on Norizuki and learns that Norizuki's girl friend, Mitsu, was a victim to their conartist group which resulted in her death. Ran is able to stop Norizuki from murdering Takeshi Motegi, Mitsu's conartist and the police arrive. For the previous murder, Conan reveals that Norizuki got off the train 15 minutes late, revealed by the exiting time on his smart card.