The president from the Republic of Poliador arrives in Japan, and the Modern Crime Prevention Task Force are assigned to assist the First Investigation Division in protecting the embassy from the outside as security personnel. Daisuke is invited inside the embassy as a representative of the Kambe Group. After the dead body of an embassy employee is discovered inside the building, the president and Daisuke are forced to evacuate to the panic room. Daisuke traces the footsteps of the suspected killer by hacking into the surveillance cameras. Kato finds the suspect as he attempts escape and tries to apprehend him.

When Cho-san was a member of the First Investigation Division 19 years ago, he and Takei were assigned to investigate the murder of Daisuke’s mother, Sayuri. At the time, Cho-san entered the Kambe residence to investigate, and Shigemaru, the head of the Kambe family, surfaced as a suspect in the case. However, the investigative task force folded due to pressure from the top brass of the police, and Cho-san was demoted. Now back to the present, after the mysterious death of Imura, the woman who Daisuke brought into the police station, Kato and Cho-san’s suspicions deepen, so they decide to enter the Kambe residence.

Aboard the cargo ship headed for Poliador, a terrorist named Weinski relentlessly attacks Daisuke and drives him into a corner. With all his new gadgets disabled, Daisuke finds himself in a pinch but is saved by Kato. They join forces again to escape from the ship. Meanwhile, at the Kambe residence, Suzue determines that the engine of the ship is being powered by a new energy source developed by Shigemaru.