The aftermath of a school shooting finds the squad trying to deal with the tragedy. Meanwhile, a traumatized Audrey returns to duty, and Nick offers support to ben, who gets suspended and must undergo therapy.
An arrest hits close to home for Nick when Kaz's girlfriend is charged with assault, and Ben begins to believe his concerns are justified. Tyler comes back to 19, and Vince's conduct is called into question.
When a young girl tries to commit suicide, Nick and Isabelle are startled to find out that Theo may be connected to the case. After her confrontation with Ben, Amelie must make a decision about their relationship.
The search for the mole takes an unexpected turn when Nick is pulled off duty. Audrey and J.M. are partnered, and Beatrice gets reacquainted with an old flame.
After an accidental death, the community erupts into violent protests. Ben and Nick suspect that one of the station leaders might be the mole, and Tyler panics during a raid of the condemned building.
Ben and Nick try to get more information from Sandrine about her father, but the homicide department calls them in for questioning in Anthony Tremblay�۪s murder.
The mole goes on the run after his identity is uncovered. The whole department is on the lookout for him, but Ben and Nick are determined to find him first.
