The Knock

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; Nolan works up the courage to ask Bailey out on a date.

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

Officer Nolan and Officer Chen search for a missing person who may have international ties, putting everyone's lives in danger; Harper continues the search for a serial arsonist; Wesley must overcome an impossible task.

When a new designer drug hits the streets, Officer Nolan and the team have a Halloween they won't soon forget; 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; Bradford is tasked with encouraging the oldest cop at the station to retire and invites him to ride with him.

Officer Nolan and Bailey discover there's more to Fred's death than meets the eye; Officer Chen and Officer Bradford demand a treasure hunt rematch and enlist Officer Grey to help set the terms to a new bet.

The team goes on a city-wide hunt for an individual who is threatening to cause a mass casualty event; Tim's sister shows up unannounced with some surprising news; Lopez continues her inner struggle over Wesley's deal with Elijah.

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; 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; 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; Tim attempts to prove he isn't a control freak to Lucy and invites her on a double date with him and Ashley.

Officers Nolan and Chen must fulfill three quests if they want to get a stolen police helicopter back safely from a teenage thief; Officer Harper and Thorson must guard a convicted cop killer in the hospital following a prison riot.

Officers Nolan and Harper help Skip Tracer Randy on his first bounty hunter case. Officer Chen and Sgt. Bradford 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. Meanwhile, 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; 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.

The team is called to investigate a train robbery; Officer Chen has doubts about being Sgt. Bradford's aid; 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; the joint task force is suspicious of the CIA's involvement in the situation.

Sgt. Grey supports Officer Nolan's desire to become a training officer and offers to ride with him for the day to get him ready; Tim and Lucy decide on their plans for Mother's Day and a romantic vacation.

Officer 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; Sgt. Bradford and Officer Chen go undercover together in a possible drug trafficking case.