L'officier Nolan est pris au piège dans sa propre maison; après avoir subi l'interrogatoire du commandant West, il propose d'être l'appât dans un coup monté contre le cartel des Derian afin de prouver qu'il n'est pas le flic corrompu du département.

Les officiers Nolan et Harper sont affectés à un centre de police communautaire; ils ont pour mandat d'aider à redorer la réputation de leur commissariat dans la communauté; Nolan est déterminé à avoir un impact positif, mais Harper a des doutes.

Nolan voit sa mère débarquer à l'improviste dans sa vie; distrait, il échoue à son examen de maniement des armes à feu, ce qui l´amène à découvrir un complot visant à assassiner une femme d'affaires; le sergent Grey envisage de prendre sa retraite.

La relation de l'officier Jackson West avec son nouvel officier instructeur, Stanton, continue à s'envenimer; il commence donc à travailler avec le sergent Grey pour trouver une solution.

Officer Nolan is taken hostage by a man with nothing to lose while the station goes on lockdown and races to identify the suspect before time runs out. Meanwhile, Officer Jackson and his training officer, Officer Doug Stanton, reach a tipping point in their relationship that could end Jackson’s career.

Officer Nolan’s decision to return to school in order to become a training officer is proving to be much harder than he expected. Meanwhile, Officer Chen considers going into undercover work after getting a taste of the job when Harper’s former colleague needs help.

The team gets the true crime docuseries treatment when they analyze a recent case featuring a former child actor whose adult life has garnered him a cult following.

Officer Nolan, Officer Harper and Detective Lopez are assigned to the kidnapping of the son of a criminal court judge who has a long list of enemies who could possibly be involved.

An Amber Alert sends the team on a race against time to find a newborn infant who was stolen from a local hospital. Meanwhile, Officers Jackson and Chen work their last shift as rookies as Officer Nolan continues on for 30 more days.

Harper and Nolan respond to a bank robbery in progress and realize the motives of the thief run much deeper than just needing money. Jackson and Chen’s first day riding without training officers isn’t what they thought it would be.

After rushing his son, Henry, to the hospital following his collapse, Nolan is reunited with his ex-wife, Sarah, and they must come together to help their son. Meanwhile, Detective Lopez discovers “La Fiera” is in the same hospital and wants to find out exactly why.

Officers Nolan and Bradford hope they can de-escalate a drug war before any innocent lives are lost. Meanwhile, Officer Harper hopes she can get Officer Chen ready to go undercover.

Officer Nolan mildly injures himself while chasing down a shoplifter and the local DA wants to charge the suspect with assault despite Nolan's wishes. Meanwhile, Lucy goes undercover, Lopez' wedding venue is seized by the FBI and Nolan meets his new neighbor.