Han Tae Joo's pursuit of his father's killer and the intangible Kim Min Seok gets more distant as the detectives of Insung are baffled once again when another murder case arises. Nothing seems to be certain. However, the body of the dead woman leads Han Tae Joo and the team to her house where they find traces of Kim Min Seok's existence. Can all of these murders be connected, but how?

With the prime suspect ending up dead during questioning, the detectives of Seobu are thrown into confusion, having doubts and suspicions of one another. However, they press on unsupported and get closer to catching the real culprit. As things start to turn for the worst, Han Tae Joo receives a phone call from someone who tells him a way to get back home.

The serial killer kidnaps Na Young. Her life is in danger. All the clues in her kidnapping are the same as the incident that happened in 2018, but this time, Han Tae Joo won't let him get away. Na Young has been missing for over nine hours, and the detectives are put to the test to save her life. Will they find her in time?