Haru Kato, a detective working for the Modern Crime Prevention Task Force in the Metropolitan Police Department, has been ordered to work on security at the Classic Car Festival being held in Ginza. At the event, he runs into his former colleagues from the First Investigation Division, who were called in because of a bomb threat. As the time until the bomb is set to explode quickly approaches, he suggests that they should cancel the festival but no one listens to him. In this tense situation, Daisuke Kambe, who claims to be the newly appointed inspector, arrives on the scene.

After escaping from the cargo ship, Daisuke and Kambe pursue Shigemaru and arrive at the old site of the 3rd Laboratory owned by the Kambe group, which is the source of all the mysteries. Daisuke confronts Kikuko, the head of the family, with his burning questions, but her answers force him to make a crucial decision. The truth behind the tension and conflict between the three generations of the Kambe family becomes clear.