Nick and Ben are set on taking down Inspector Elise Roberge in order to avenge the brutal murder of Nick's sister. Nick is first on the site of a horrific event with numerous casualties. Meanwhile, Ben and Audrey are implicated in a tragic accident.

With the investigation of Elise Roberge over, Ben volunteers for surveillance duty. Ben and Audrey face the consequences of their accident. The squad ends up in the middle of a growing gang war.

Ben's actions bring repercussions. Ben and Nick seek justice for a raped prostitute and encounter someone they both never thought they'd see again. A new officer joins 19. The squad finds out something disturbing about one of their own.

The squad escapes to a cottage for the weekend, where alcohol and the intimate setting lead to conflict.

Ben faces consequences. Nick's new romance gets complicated. Dulac crosses a line; Audrey thinks about the future.

Ben's troubles become public, Nick faces a crisis and Dulac gets in over his head.

The squad works during a full moon. Suarez and Beatrice receive unexpected news. The squad works to prevent a tragedy.