Detective Tze-Wei attempts to protect a sex worker who resists her help, as her precinct battles the city councilor in a feud that dates back a generation.

Tze-Wei becomes consumed by a dark tragedy from her past after learning the identity of a recent homicide victim in a case with striking similarities to a murder that took place 23 years ago.

As he gears up for re-election, Chi-Hsiao is hit with an assassination attempt; while Tze-Wei believes it may have been a warning shot, the shooter has a bigger agenda.

Tze-Wei is assigned to Chi-Hsiao's security detail; Chia-Hao clashes with his boss; Ching-Yao discovers a body while hosting his friends from Hong Kong.

When the body in the suitcase is identified, the team is rocked by the case's similarity to a murder Tze-Wei's father confessed to 23 years ago and the copycat murder of Chia-Hao's girlfriend three years ago.

Tze-Wei, Chi-Hsiao, and Chia-Hao team up off-the-clock to pursue a forbidden suspect; they're in for a surprise when confronted by an even more dangerous criminal.