The team begins narrowing down the culprit. They compile a list of home addresses where the water usage has been unusually high. While investigating, Ji Han finds Detective Choi Hyun Seok’s wheelchair and a rifle bore-cleaner next to it. Suddenly, Oh Jong Cheol, another detective, greets him warmly and invites him over to his house.
합동수사본부 팀은 수사 도중 전혀 예기치 않은 인물을 만나게 되고, 드디어 진범이 모습을 드러낸다.