Seoul city's metro police investigative squad meets its 30th anniversary and tasks to convict a petty thief. Yoo-ryung reads an advertisement for new recruits and applies to the squad. She is unsuccessful in application.
Yoo-ryung hears suspicious noise whilst on patrol, and enters an off-limit area. Captain Go Ji-seok,finds Yoo-ryung unconscious and warns her never to enter again.
Investigator Yoo, faces internal review for shooting at a felon who trampled on the face of the police. The review board takes the issue very seriously in-order to avoid the blames of the media.
The Seoul city metro investigative squad investigates a case of contract killing. The squad seeks evidence and witnesses.
Kim Won-tae is arrested for charges of assault and battery, and upon search of his history it is revealed an ex-girlfriend was murdered. His girlfriend declines the need for an apprehended violence order.
Captain Go and Yoo-ryung experiment with a rumor which states, on the last friday of every month, an all-night clubber disappears on the first train. Captain Go tails a petty thief.
Moon Geun-young
Yoo Ryung
Kim Seon-ho
Ko Ji Seok
Jung Yoo-jin
Ha Ma Ri
Ki Do-hoon
Kim Woo Hyuk
Jo Jae-yoon
Lee Man Jin