Tired after working at an amusement park, Hajime Kindaichi is on a train home when he is accused of murdering the loan broker Ekuma Tadao on the train and arrested. Hajime claims he is innocent and Akechi promises that he will seize the real killer. Now in jail, Hajime's fate depends on the detective skills of Inspector Akechi. Akechi commences his investigation by analyzing the crime scene, questioning the witnesses and probing Tadao's background...