A new designer drug is killing kids. Jimmy and his team dig and in turn the city upside down looking for the dealer. Once again Jimmy turns to Han, but he's holding back. Having moved up in the Dragon's Shadow organization. Yolanda finally faces the truth and decides to come to clean her past, but it may be too late. The Internal Affairs investigation is hitting a wall and Robert Zakia and his Partner Miriam Garcia, redouble their efforts putting pressure on Jimmy, hoping he'll crack. Tarik, Yolanda, and Tess are left to solve the case on their own. Jimmy's meeting with Darius results in disastrous consequences. Dead bodies start to mount, and personal lives are torn apart as the head of the Albanian Mob, Argon, finally discovers who took his money, but more importantly, Argon finds out who killed his son.

Yolanda and SIU throw themselves into solving Jimmy's case. Miriam works alongside SIU. Respect growing between them. They retrace their steps. They follow old leads. When left with the facts they can come with only one conclusion … SIU has a dirty cop. Now the four of them are isolated and have to work outside the system. Yolanda and Tarik follow a lead and find Darius with Argon. A final confrontation between Yolanda and Darius leaves the team with only more questions. All the while Jimmy's life hangs by a thread in the powerful season finale of Bronx SIU.

Chief Wryles breaks his silence and give us a glimpse into his master plan. But, his world goes sideways when Darius resurfaces and blackmails him. SIU has its hands full with a bizarre murder triangle of a high-end fashion model. Gloria admits a painful secret she's been hiding from Jimmy and Jasmine is battling her own demons as she confronts her feeling about Yolanda.

The team's personal and professional life come crashing together. Argon manipulates SIU to his own ends, while Han plots a bigger goal. Tess and Tarik try to hold down SIU as Yolanda becomes more erratic. She reaches out to Jimmy, only for him to shut her out. Jimmy and Darius finally meet, but it can only end at gun point. No one escapes the disastrous fallout of this episode's season finale.