A new murder case involving a fire appears to have similarities to one from Kang Seong-mo and Lee An's past. Meanwhile, Yoon Jae-in follows a peeping Tom.
Lee An fights to prevent his expulsion from school, and finds an unexpected ally in Jae-in. Meanwhile, Eun Ji-su finds a break in the murder case.
Keeping the truth about her family hidden from her classmates, Jae-in heads to her part-time job; another victim appears in Seong-mo and Ji-su's investigation.
Two years later, Jae-in is working as a police officer, while Lee An is attempting to become one; Ji-su lets Seong-mo know about her blind date.
The request of a favour makes Jae-in pause and need persuading; Lee An realises that someone is following Seong-mo.
A mystery involving a dead woman leaves the police struggling to find answers; Jae-in attempts to help Lee An focus his abilities.
J.Y. Park
Lee Ahn
Shin Ye-eun
Yoon Jae-in
Kim Kwon
Kag Sung-mo
Jo Byung-gyu
Sung-mo
Kim Da-som
Eun Ji-soo