Detective Yeong-han's capture of the gang's second-in-command, Viper, sparks chaos at the station.

Yeong-han recruits to Unit 1 the fiery Sangsun, the might Gyeonghwan, and the elite Hojeong.

Yeong-han warns of robbers heading to Seoul, but Senior Superintendent Choi dismisses his concerns.

Yeong-han suspects the orphanage director's involvement while delving into a missing infant case.

Devastated by the sudden death, Yeong-han sets a trap to apprehend the prime suspect, Sal Mo-sa.

Notable changes have reached Jongnam Police Station, where Baek Do-seok, a former military policeman, becomes the new Senior Superintendent.

One January morning, a tragic suicide case falls upon Unit 1. Despite Do-seok's interference, Yeong-han persists, uncovering a grander truth.

A brutal mugging occurs upon drunk pedestrians overnight. With all other officers engaged elsewhere, Unit 1 responds to the case.

Yeong-han learns of peculiar disappearances at a textile factory. Clues reveal the involvement of the influential "Tennis Boys Club".

Unit 1 locates the missing female workers and seeks their testimony, capturing Do-seok's attention. Do-seok's scheme backfires as Yeong-han thwarts it.