The entire squad is embroiled in an intensely tragic school shooting with consequences that will profoundly impact all of their lives.

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

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

The squad is devastated when one of their own is brutally assaulted and left clinging to life, causing personal vendettas to collide with protocol in the aftermath.

Nick and Ben will be forever changed by a tragedy caused by a misunderstanding.

Nick and Ben discover the truth behind Amelia's death.

Nick and Ben deal with the aftermath of a tragedy. Nick's lies threaten to drive them apart.

The squad waits for findings from a task force into Sergeant Houle’s case. Nick and Ben find themselves at the centre of the fractured squad, the only partnership that has endured. On the job, the squad face a horrific accident that puts multiple lives in danger.

The first of the month brings “Welfare Day” to 19 – Nick and Ben handle an array of belligerent civilians; the day caps off with a cataclysmic domestic disturbance.

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 identity of the mole is revealed.

The patrollers of 19 struggle to find their footing. Nick realizes what he wants. Dulac loses control.

Tyler botches a takedown of a gang of rapists that nearly costs Nick his life, and leaves Ben to question Tyler's fitness on the job. Nick brings Harvey to Houle’s BBQ, which goes crudely awry.

A cover-up comes back to haunt Nick and Ben, pitting them against Gendron. Nick’s frustrations mount when Ben encroaches on his personal life.

In the climactic season finale, Nick receives devastating news, and struggles to contain his explosive response. A surprise visitor lands in Ben's life, forcing him to make some very hard decisions.

The squad becomes involved in a feud with firemen; little mistakes cause consequences.

Amelie takes a chance on Ben, while Nick and Isabelle receive shocking news about Theo.

With the mole on the run, a devastated squad turn on each other, and on themselves.

Nick investigates his cousin's death and finds a possible witness.

When he tries to help Nick with his investigation, Ben gets in trouble with homicide.

The city cuts public sector pensions, pitting the squad against their own.

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.

Nick butts heads with J.M when they are assigned patrol together. Beatrice embarks on a new romance.

In the aftermath of the school shooting, the squad copes with the trauma as it affects them in ways they never expected.