Trinity of Shadows

As Detective Tze-Wei leads an assault case and attempts to protect Nicole, a battered and harassed sex worker, elsewhere on the force, rookie Chia-Hao lies to their chief about the status of a pressing case. Later, when City Councilor Chi-Hsiao Yang levies accusations against the Commissioner, the force slaps an inspection on Yang's hotel, landing Tze-Wei in the very location where she was shot three years before.

After an over-the-top interrogation of Nicole's stalker, Tze-Wei is relegated to desk duty, while the rest of her team investigates a murder. But upon learning the identity of the victim, Tze-Wei begs to work the case -- until Chief Huang shares a troubling similarity to a murder from 23 years ago. Meanwhile, Chia-Hao successfully follows a tip to locate escaped migrant workers, and Chi-Hsiao hits a wall when he tries to expose a corrupt political situation.

After Tze-Wei is assigned to Chi-Hsiao's security detail, they find a surprising connection. Meanwhile, Chi-Hsiao is approached by Jia-Jia with a problem, Chia-Hao has a physical altercation with his boss, and Ching-Yao finds another dismembered body at the lake.

When the body in the suitcase is identified, Chi-Hsiao takes the news especially hard, and Chia-Hao is triggered by a painful memory, which inspires him to finally request a transfer to the coveted Crime Investigation Department. Later, Tze-Wei and Chia-Hao discover a potential link in multiple unsolved murders.

After Tze-Wei is thrown off the murder case for pursuing the Chief Prosecutor's son, Ming-Chieh, as a suspect, her superior-ranking ally, Lio-Li, promises to feed her information. When Chi-Hsiao is blackmailed by a political rival, he must rein in the rest of team, while Chia-Hao recruits their help with a little side investigation of his own.

After losing faith in the system, Chia-Hao goes rogue to pursue a personal vendetta. When Ming-Chieh is kidnapped, Tze-Wei puts personal feelings aside to work the case. Meanwhile, as Chi-Hsiao holds his director accountable for a violent act, his entire staff unites against him, and a security tape reveals a surprising connection between Ching-Yao and Jia-Jia's last client.

Tze-Wei protects Chi-Hsiao from wanted criminal Ta-Dong, even as he begins to make ominous threats toward her. Chi-Hsiao shares an unflattering truth about his past to gain back his staff's trust. Even as his personal and professional secrets unravel, Chia-Hao proves to be a formidable enemy, and Ming-Chieh grows closer to flipping Chia-Hao's partner.

While Tze-Wei and Chi-Hsiao beg him to let go of Ming-Chieh, Chia-Hao continues to press both Ming-Chieh and Ta-Dong for more details about Chien-Chien's last night. Then, in a final act of friendship, Chia-Hao advises Tze-Wei to figure out why Ta-Dong is so intent on making her an indirect target.

As Chi-Hsiao opens up about his painful past, Tze-Wei realizes that their similarities are driving them toward the same goal in the present. Then, a nice day of sight-seeing with Ching-Yao and his girlfriend turns sour when Tze-Wei is abducted.

Tze-Wei escapes her captor, only to then realize she's played right into his plan. Chi-Hsiao makes a confession that brings him and Tze-Wei closer than ever. A tattoo sheds light on Ta-Dong's secret past, and when Tze-Wei is falsely accused of murder, she learns an unfortunate truth about Ching-Yao.

Tze-Wei fights to prove her innocence but gets more than she bargained for in her pursuit of the truth. Against the advice of his father, Chi-Hsiao withdraws from the election after personal and political lines blur. Later, Ta-Dong holds the key to Susanna's undoing, and Ching-Yao risks it all to protect her.

As the media reveals Ta-Dong as the suspect in the latest murder, Tze-Wei is unwillingly transferred to another region and Chi-Hsiao grows conflicted over a new wrinkle on the event from 23 years ago.

Tze-Wei finally learns the shocking truth behind Chi-Hsiao’s mother’s murder, and then is forced to re-experience their shared trauma. Chi-Hsiao turns down a chance at revenge, working together instead with his mother’s murderer to save Tze-Wei and Ta-Dong makes a fatal ultimatum.