40 years old and single, Osawa Eriko, a former career official is selected to be the head of the First Investigative Division’s newly established Special Crimes Unit upon her return from America. Eriko had a promising future ahead of her but some scandal caused her demotion and she went to study in America on the pretext of training. She spent 5 years learning at the FBI and has just returned to Japan.

Nodate Shinjiro, an aide to the counsellor and Eriko’s contemporary, was the person who had led the establishment of the Special Crimes Unit. Nodate explains to journalists gathered at the Metropolitan Police Department that the Special Crimes Unit is a team that will address violent crimes through specialised investigations like forensic science.

Happy to be working as a detective again, Eriko meets the detectives that have been assigned to the Special Crimes Unit. She had heard that they are an elite group but the members are Kimoto Mami, who has been thrown out of the Forensics Science Unit because she cannot wake up in the morning; Katagiri Takuma, who is disgusted to belong to the organisation; Yamamura Keisuke, a man from the Community Safety Division with the nickname of Metropolitan Police Department’s biggest blunderer; Hanagata Ippei, a rookie detective who only has more motivation than others; and Iwai Zenji, who has been thrown out from the Organised Crime Division because of his involvement in violence. They can hardly be called elite detectives.

Eriko’s appointment as the first female unit head of the First Investigative Division pays off and is well received by the mass media. The top brass of the Criminal Affairs Department, head of criminal investigations Tanba Hirohisa and counsellor Yada Kenzo, snicker that even if the Special Crimes Unit were to end in failure, it would be a setback for Nodate.

As this is taking place, the unit receives a report that the charred body of an unidentified man has been found at the river bank of the Arakawa. Strangely, only the upper torso had been burnt and one of the arms is broken. Eriko immediately heads to the scene with Mami and Katagiri. However, they are treated like a nuisance by the detectives of the First Investigative Division and turned away. The head of the First Investigative Division Onoda Tadashi declares to Eriko that the First Investigative Division brings together the best men so she should back off.

Before long, the identity of the victim is determined. He is Maeda Satoru, a black market financier who charged exorbitant interest. Narahashi Reiko, the Forensic Unit’s medical examiner reports to Eriko that the cause of death was heart failure but there were chemically synthesised materials that had stuck to the skin on his upper torso when the explosion had occurred. She also knows that Maeda had gone up the steel tower at the scene just before he died, had suffered a heart attack and had fallen down after his death.

There is finally proof to indicate that Maeda had been threatened by someone and made to go up the steel tower against his will. It also emerges that the dead body of a homeless person with a charred upper torso just like Maeda’s had been found. Eriko deduces that these are serial murders which were committed by the same criminal using explosives. There is a strong possibility that the criminal is a technician who isn’t highly educated and a third murder will definitely be committed sometime soon.

A new victim emerges, just as Eriko had conjectured. The victim is Kojima Fumihiko, a bank employee. At that moment, a man thought to be the culprit is arrested. That man is Nogaki Taizo, the owner of a local factory that handles chemicals.

Nogaki is thought to have planted the next bomb but he is evasive, warding off questions during the interrogation so the detectives are unable to obtain information from him. Then Eriko takes over the interrogation, prodding the proud Nogaki with a bluff, she eventually makes him tell her how to defuse the bomb.

The fourth target is Noguchi Yoko, the president of Koukyou Chemicals who has caused the decline of Nogaki’s factory. Noguchi, who is outfitted with a bomb in the style of a vest made by Nogaki, has a terrifying time. The bomb disposal crew that has arrived there defuses the bomb with the information from Eriko. Noguchi narrowly escapes death.

Eriko’s big gamble with Katagiri and the rest had not only completely fooled Nogaki, but also Onoda and the detectives of the First Investigative Division, Nodate and Mami. Anyone who had seen her skill couldn’t help but think that it was splendid. The members of the Special Crimes Unit begin to realise the importance of Eriko’s existence in the days since she took up the position as the head of the unit.

Meanwhile, Eriko, who has finished work, walks along the streets with light steps. Then she sees the figure of a person standing in wait. A smile lights up her face and she rushes over. The man, Ikegami Hiroshi, who is dressed like a blue-collar worker, smiles at her. They exchange glances and seem to have the happy mood of a pair of lovers …