Season 1

On her birthday, Yoon Ji-woo witnesses the horrific death of her father. Hell-bent on taking revenge at any cost, she sets out to find his killer.

Choi Mu-jin imposes punishment on Do Gang-jae. Instructed to join the police force undercover, Ji-woo takes on a brand-new identity.

When her team goes after an unforeseen target in a sudden raid, Ji-woo must act fast. A new drug ring and its malevolent leader threaten Mu-jin's empire.

Cha Gi-ho sees Gang-jae's declaration of war on Mu-jin as an opportunity. Suspecting Ji-woo is up to something, Jeon Pil-do tails her.

Ji-woo and Pil-do's narrow escape from peril shifts the police's focus onto Gang-jae. A run-in with a familiar face at the precinct places Ji-woo on edge.

A photo in the mail revealing obscured truths casts everything Ji-woo thought she believed into doubt. Mu-jin moves to protect his interests.

Ji-woo fights off an ambush. Mu-jin submits himself to a police interrogation. Pil-do gets his hands on incriminating phone call records.

Intent on changing Ji-woo's mind about carrying out her vengeance, Pil-do handcuffs himself to her. Mu-jin reacts to another act of betrayal.