A good deed turns out to be the wrong move - leaving Ye-bun in a tough place. Jang-yeol later joins her in tracking down a dangerous figure.

Jang-yeol and Ye-bun recruit key townspeople to collect important information. But Ye-bun comes across a shocking vision related to her past.

Ye-bun begins learning new information about her mother's death. The search for the perp continues, and everybody becomes a suspect.

Ye-bun ask Jang-yeol for help in finding answers about her past. As a political ally slowly becomes a foe, Ye-bun confronts her grandfather.

One wedding (is announced) and a funeral. Jang-yeol is unexpectedly sensitive to Ye-bun's suffering. Seon-woo's absence is marked as suspicious. Captain Jong-muk and his team are forbidden from investigating the serial killer case and are directed to "protecting people's livelihoods." As one suspect after another is eliminated, Jang-yeol goes back to the beginning and questions all of his conclusions. Ye-bun bursts into his home with a theory that connects all new dots in a terrifying way.

Frustration and grief are running high in Mujin as Detective Jang-yeol and the police track down new leads in a dwindling pool of suspects. Yet another murder is committed, and Jang-yeol is maddened with frustration as the serial killer seems to slip again and again through his fingers. Even so, he makes a shocking discovery and confesses it to Ye-bun. She manages to avoid all efforts to keep her safe, and as Jang-yeol races to her rescue, he may already be too late.

Another death at the hands of the serial killer leaves both Ye-bun and Jang-yeol stunned, grieving, and guilt-ridden in their own ways. The victim provided them with the evidence to convict the killer, but the killer brags they have one shot left, and demands to be released in exchange for the life of the final victim.

Before there can be a happy ending, there must be a rescue, a recapture, some goodbyes, a proposal, some baby talk, a television appearance and an invitation to a date.