Yukiko Makabe was a senior officer on the Special Investigations Team, but was reassigned after she took responsibility for a failed bus hijacking case. She was transferred to the Department of Grill Room Investigation. Since the department is specialized in conducting important investigations, only the best made it into the group. Surrounded by veteran investigators with unique personalities, Yukiko starts her new career. Her job will be to uncover the hidden truths by interrogating suspects that are far from ordinary. This is a new police drama that focuses on the battlefront behind closed doors.

With unique veteran investigators, Yukiko Makabe uncovered the hidden truths through interrogations in the Emergency Interrogation Room (EIR), until the team fulfilled its role and was disbanded in 2021.

— 4 years later. A series of shocking murders shakes the nation. The suspect is a wildly popular news anchor. To settle the situation, Prime Minister Yojiro Osanai orders the reassembly of EIR.

In the final season of this drama series, EIR faces its greatest challenge yet—taking on seemingly invincible suspects! In the closed interrogation room, they clash souls and engage in fierce verbal shootouts!