Talia forces Nolan to confront his personal moral instincts in order to be a good cop after he encounters a kidnapping victim. Lucy is temporarily placed with a new training officer who tests her patience. Jackson must confront his failures head-on if he wants to be an officer.

After Nolan and Talia lose control of a crime scene, they begin to debate whether people are fundamentally good or bad and what that means for a police officer. Lucy is concerned Tim is enabling his wife’s destructive behavior and not taking care of himself.

The rookies are temporarily paired with new training officers, and Nolan is paired with Lopez. When Nolan and Lopez track down an escaped criminal, they discover a little kindness goes a long way. Jackson is forced to face his fears when he is partnered with Officer Bradford. Chen and Nolan must face a hard truth.

Nolan, the rookies and their training officers get involved in a competition that pits them against each other. Chen notices Bradford is obsessed with winning at all costs.

Nolan and the team must help capture a cop and his former mentor from the academy after he becomes a fugitive following an assault. Bradford needs Chen to learn to predict the moves of criminals in order to capture them.

Grey informs Nolan and Bishop that they are going to have a movie director as a ride-along during their patrol after a fun afternoon granting the wish of a Make-a-Wish kid as an honorary police officer. Bradford is tested once again after he learns that his wife has been arrested for drug possession.

Nolan and Bishop respond to a silent alarm call at a local convenience store where two men are attempting to rob the place. Bishop helps coordinate a drug bust that hits a little too close to home for Bradford.

Officer Bradford’s wife, Isabel, is found shot but alive and he vows to track down the man responsible. Meanwhile, Officer Nolan must protect his home and the truth after a home invasion attack.

On Captain Andersen’s orders, Officer Nolan and Sergeant Grey are paired up for the day on patrol. Additionally, Nolan’s son and Grey’s daughter visit their dads on the job and see them in action. Meanwhile, Officer Chen is paired up with Captain Andersen, and Officer Bradford tells Chen to protect her at all costs.

An unscheduled visit by the vice president of the United States puts the station on high alert. The secret service tasks Officer Nolan and Officer Bishop with checking out a possible threat to the vice president while the rest of the team try to keep the streets clear and safe for his visit.

The most dangerous day of the year – Valentine’s Day – has the team on high alert, and Officer Nolan invites everyone over for a party now that he is single.

The rookies become the prime suspects after it is discovered a large sum of money used in a drug bust has gone missing.

Officer Nolan and the entire team are in a desperate search to rescue Officer Chen after her abduction and must attempt to get Rosalind to help them in their search. Meanwhile, after Officer Lopez discovers Wesley unconscious from a dangerous cocktail of alcohol and pills, she is forced to keep him close by.

Nolan takes his son’s fiancé, Abigail, on a ride-along after she shows interest in becoming a police officer. Meanwhile, Jackson’s relationship is becoming complicated at work.

Nolan is given some life-changing news and invites Grace over for a homecooked meal in his newly remodeled kitchen. Meanwhile, each unit is tasked with following up on dormant cases in the hopes they can uncover new leads.

Officers Nolan and Harper investigate a murder which may have national security implications, while Officer Bradford must confront his past when he crosses paths with a homeless veteran.

Officer Nolan is having a particularly bad day after learning his identity has been stolen and could jeopardize his position as an officer. Meanwhile, Sgt. Grey must confront his past and testify at the parole hearing of the man who shot Grey and murdered his partner.

Officers Chen and Bradford respond to a call at the Los Angeles auditions of “American Idol,” and Officer Chen ends up facing Ryan Seacrest and the judges. Meanwhile, Chen befriends a reporter whose motives are not clear.

Officer Nolan’s relationship with his first confidential informant is tested when he discovers her back on the street dealing drugs. Meanwhile, Lucy’s fear of dating following her abduction and her intrusion into Jackson’s relationship is beginning to threaten their friendship.

Officers Nolan and Harper are tasked with escorting four juvenile offenders to a Scared Straight program at a correctional facility that quickly becomes a riotous situation. Meanwhile, Nolan is uncertain about his relationship with Grace after she fails to introduce him to her ex-husband.

Their rookie year is coming to an end and officers Nolan, Chen and West are about to be squeezed harder than ever before as their training officers evaluate whether they are truly ready for the job. Meanwhile, after one of their rookie classmates is involved in a shooting, the team uncovers some unsettling evidence .

Nolan's discovery goes much deeper than he expected and could put his life and career in jeopardy.