After Okihara is attacked by someone, the suspect in Higuchi's wife's murder appears on the investigation timeline. However, Higuchi and Tachibana speculate that the real murderer is elsewhere.
Uesugi commits suicide. However, Tachibana doubts that it was a suicide. Higuchi and Tachibana wonder why Hongo's son, Shizuku, has not cooperated with a witness interview for the murder of Okihara.
Higuchi heads to the scene of an accident at a construction site involving Hongo Holdings. At the same time, Higuchi hears that there was an accident at another construction site also involving Hongo Holdings.
Higuchi rushes to Shizuku's vacation home and finds Shizuku's car and someone's bloodstains. Convinced that Ishikawa, who has been missing, may have been involved in the case, Higuchi raids the vacation home.