Se-hyuk, a jaded detective, nears quitting and serial killer Yang Do-soo confesses; Se-hyuk doubts him, gets sued.

Min-ju is jailed by Se-hyuk due to her boss's quest for website views; Dong-seok's case raises suspicions about Se-hyuk's daughter Hae-in, leading Se-hyuk to question Il-do and escalate their conflict.

As police tighten their siege, Lee Dong-seok leaves Se-hyuk with a cryptic statement about his daughter's death and vanishes; the mysterious message adds a new layer to the investigation, leaving Se-hyuk perplexed and searching for answers.

Se-hyuk is investigated for Lee Dong-seok's case and confronts Il-do; the detectives work on the murder of the plastic surgeon and Seol-hee, CEO Min and Kang Sung-chul are listed as suspects; Min-ju gets a hunch and investigates Seol-hee's past.

The Violent Crimes Unit detectives watch a ballet performance of "Romeo and Juliet" and witness Cha-soo-yeon's death on stage; the concert stops, and Il-do takes over the crime scene.

Se-hyuk is confused as Yoon Sung-hee, his suspect, dies like Cha Soo-yeon; Il-do directs probe to possible homicide.