Starting over isn't easy, especially for small-town guy John Nolan who, after a life-altering incident, is pursuing his dream of being a police officer. As the force's oldest rookie, he’s met with skepticism from some higher-ups who see him as just a walking midlife crisis. Throw in a workplace romance, a hostage situation, and some tough love from their new training officers, and the latest Los Angeles police rookie class has an uphill battle ahead of them.

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.

The rookies are really put to the test when their training officers accompany them out of uniform for Plain Clothes Day, which forces them to make all the decisions while on patrol. Meanwhile, Officer Nolan tries to prove he has been progressing faster than the other rookies to justify his desire of becoming a detective within five years.

When a prison bus crashes, all units must respond as some inmates face severe injuries while others seek an opportunity to flee. In the wake of the accident, Officer Nolan tries to impress an FBI hostage negotiator while tracking down an escaped convict.

Officer Nolan gets a lesson in respect after his arrest of a gang member leads to a free-for-all on his life. Meanwhile, Officer Chen and Officer Bradford pull over Mario Lopez, who thinks he can talk his way out of a traffic violation.

A massive earthquake rocks the city and throws everyone’s patrols and its citizens into chaos. Meanwhile, agent Russo recommends Officer Nolan for a protective detail of Brad Hayes, a man whose dealings have put a target on his head.

When one of their colleagues is arrested by Internal Affairs for lying on the witness stand, it leads to the release of three felons whose cases he worked on and the team being asked to check in on them now that they are free. Meanwhile, Officer Nolan finds out he is being sued by a man who claims he used excessive force which led to an injury.

Sergeant Gray informs the rookies that they must track down a specific set of crimes in a 48-hour period in order to qualify for their final exam. Meanwhile, Officer Nolan and Officer Bishop answer a silent alarm call at will.i.am’s house.

As the rookies prepare for a big exam to see who moves on to the next stage of training, Officer Nolan and Officer Bishop are called to the scene of a murder and learn that the victim may be tied to a potential terrorist attack on the city of Los Angeles.

Officer Nolan and the entire team race against the clock to locate Lopez after she is kidnapped on her wedding day, not only to save her life but her unborn child’s.

Officer Nolan and Officer Chen’s run-in with an infamous thief tips them off to a potentially big heist surrounding the Getty’s big gala event. Meanwhile, Nolan works up the courage to ask Bailey out on a date.

Officer Nolan and officer Chen report to a structure fire and suspect that there is more to the situation than meets the eye. Meanwhile, after witnessing a sniper shooting, the team searches for the shooter and discovers that the perpetrator has a connection to one of their own.

Officer Nolan and Officer Chen search for a missing person who may have international ties that puts everyone’s lives in danger. Meanwhile, Harper continues the search for a serial arsonist after responding to a report of an injured cyclist, and Wesley must overcome an impossible task.

When a new designer drug hits LA streets, it turns users into “zombies,” and Officer Nolan and the team have a Halloween they won’t soon forget. Back at home, Lucy questions whether her apartment building might be haunted.

Officer Nolan and team are on a hunt to retrieve a buried stash of gold before any treasure seekers get hurt. Meanwhile, Bradford is tasked with encouraging the oldest cop at the station to retire and invites him to ride with him.

In the aftermath of Fred’s house explosion, Officer Nolan and Bailey discover there’s more to Fred’s death than meets the eye. Meanwhile, Officer Chen and Officer Bradford demand a treasure hunt rematch and enlist Sgt. Grey to help set the terms to a new bet, all while they arrest a series of wealthy female criminals. Elsewhere, Wesley struggles to keep it together under the pressure of his debt to Elijah.

The team goes on a city-wide hunt for an individual who is threatening a mass casualty event. Meanwhile, Tim’s sister Genny shows up unannounced with some surprising news, and Lopez continues her inner struggle over Wesley’s deal with Elijah and tries to come up with a plan to get them out of it.

Desperate to break free from his connection to Elijah, Wesley tries to plant a listening device in his office to incriminate him; Officer Bradford and his sister, Genny, learn an unsettling truth about their father.

Now that John Nolan knows about Bailey’s past, he must decide if they still have a future. Meanwhile, when a plane crashes in the middle of the city the team races to find out why.

The team must rely on a criminal for his expertise to help take down an even bigger threat. Meanwhile, Officers Chen and Bradford investigate the murder of an unhoused teenager who used to be friends with Tamara.

The team responds to the report of a severed hand washing up on the beach and are on the hunt to find its owner. Meanwhile, Tim attempts to prove he isn’t a control freak to Lucy and invites her on a double date with him and Ashley.

Officers John Nolan and Lucy Chen must fulfill three quests if they want to get a stolen police helicopter back safely from a teenage thief. Meanwhile, Detective Nyla Harper and Officer Aaron Thorsen must guard a convicted cop killer in the hospital following a prison riot.

Officer Nolan and Detective Harper help Skip Tracer Randy on his first bounty hunter case. Meanwhile, Officer Chen and Sergeant Bradford are on the hunt for a perpetrator on a citywide crime spree.

Officer Harper puts Officer Aaron through “Plain Clothes Day,” but the exercise is interrupted by an unsuspected visitor. After two witnesses for an upcoming grand jury case are murdered, the team must track down the killers before it’s too late.

Desperate to reset the way the world sees him, Officer Thorsen reluctantly decides to be a part of a reality show to help rebrand his image, only to be thrust back into yet another deadly situation. With cameras rolling, the show’s producer is found murdered and the team must investigate before Aaron is made suspect number one.

Officer John Nolan and the team feel they must negotiate with a distraught man who is holding a hospital hostage to ensure his wife receives a lifesaving surgery.

After the robbery of a train filled with valuable auction items turns deadly, the team is called to investigate. Meanwhile, Officer Chen has doubts about being Sergeant Bradford’s aide and is upset when he doesn’t give her the recognition she deserves. Elsewhere, Officer Harper takes matters into her own hands and makes a life-changing decision about her personal life.

Officer Nolan and the LA division of the FBI enlist the help of FBI trainee Simone Clark when one of her former students is suspected of terrorism following an explosion at a local power station.

The team alongside the LA Division of the FBI are in a race to stop bombs that have been scattered throughout the city by a suspected terrorist. Meanwhile, the joint task force is suspicious of the CIA’s involvement in the situation.

Sergeant Grey supports Officer Nolan’s desire to become a training officer and offers to ride with him for the day to get him ready. Meanwhile, Tim and Lucy must manage expectations in their respective relationships as they decide on their plans for Mother’s Day and a romantic vacation.

Officer John Nolan is forced to spend a week in solitary confinement in a quiet border town with a young local officer who is in need of some training. Meanwhile, Sergeant Bradford and Officer Chen discover that looks are deceiving and go undercover together in a possible drug trafficking case.