Guilt ridden Officer Nick Barron returns to work following a deadly shooting; Ben Chartier's transfer to Station 19 from Québec's rural police force turns rocky after a split-second decision triggers an internal investigation.
A showdown between rival street gangs goes terribly wrong, leaving Ben’s life in danger. Squad 19 gathers at Marie’s for the Sergeant’s party and Isabelle discovers Nick may have feelings for someone else.
An amber alert ripples through 19. After realizing he’s been shutting Audrey out, Nick makes a strong commitment to her. Ben continues to date Amelie without telling Nick, adding another stress to their partnership.
Nick and Ben decide to take down Elise to avenge the brutal murder of Nick's sister. Also, Nick is first on the site of a horrific event with numerous casualties, plus Ben and Audrey get swept up in a tragic accident.
Ben's actions bring repercussions; in pursuit of justice, Ben and Nick encounter a person they thought they'd never see again; a new officer joins 19; the squad finds out something disturbing about one of their own.