A burnt corpse of a man was found in Okutama. As a result of the investigation, it turns out that the criminal strangled the victim with a bandage, smashed his face with an oil canister and burned the body, trying to hide the identity of the victim. But the investigation establishes that the victim is a former criminal named Hisashi Sayama. According to the daughter-in-law of the Sayama, a man named Kitamura got him a job, so he left home with a copy of the family register. Trying to find the killer, the First Investigation Department is investigating all over the country, including Akita, Yokkaichi and Okinawa.
An elderly woman, Ume Matsumoto, complained to the First Investigation Department that her son Hirasaka, who runs a shoe store, had disappeared. The ominous foreboding of the First Investigation Department hit the mark, it turned out that the discovered unidentified body of the drowned man was Hirasaka. Moreover, the land in front of the station, owned by Hirasaka, was sold by someone. Suspecting that this is a planned murder, the Investigative Group, fearing the escape of the criminal, begins to act secretly, without creating an investigation headquarters.
On a quiet spring day in the suburbs, a stray dog found the corpse of a baby. Three days after his death, the blood group of the victim was determined. Detectives Hayashi, Kaneko, Nagata and Yamagata begin their investigation, suspecting the parents of the murdered child. They use a towel, baby diapers and bruises on the baby's body as clues in the investigation. Who killed the baby?
Based on Matsumoto Seicho's classic mystery novel of the same name, the story centers around a group of detectives who are determined to find the truth behind an apparent double suicide.
