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

Choi Mujin imposes punishment on the Do Gangjae; instructed to join the police force undercover, Jiwoo takes on a brand-new identity.

When her team goes after an unforeseen target in a sudden raid; Jiwoo must act fast; a new drug ring and its malevolent leader threaten Mujin's empire.

Cha Giho sees Gangjae's declaration of war on Mujin as an opportunity; suspecting Jiwoo is up to something, Jeon Pildo tails her.

Jiwoo and Pildo's narrow escape from peril shifts the police focus onto Gangjae; a run-in with a familiar face at the precinct places Jiwoo on edge.

A photo in the mail revealing obscured truths casts everything Jiwoon thought she believed into doubt; Mujin moves to protect his interests.