The SWAT team faces difficult reminders of a past school shooting when they receive a warning that a copycat plans to re-enact the crime. As the team races to stop the new threat, they flash back to the day of the tense first mission.

After an explosive accident at a fruit-packing facility staffed by prison workers, six inmates escape and scatter across the city. Tasked with chasing down the fugitives, Hondo and 20-Squad discover that the worksite explosion was no accident, and that the escapees are working together to carry out a high-stakes robbery. Also, Commander Hicks packs up his office, preparing to vacate the SWAT commander's post, and Gamble gets sobering news about her jailed father.

20-Squad faces down a prison hostage situation, only to be thrown into deeper danger when a bomb explodes, freeing maximum-security prisoners from their cells, including someone with a personal grudge against Hondo.

S.W.A.T.'s anti-terror sting operation at a bus station is thrown into chaos when felons, fleeing the police, burst in and take the bus station hostage; Bennett redoubles her efforts to force Hicks out as S.W.A.T.'s commander.

When Hondo’s cousin goes AWOL from his Marine base during basic training, Hondo, Deacon and Daniel Sr. take a road trip to get the kid in line; Alfaro plots to work outside the law when he discovers that his mother’s abusive ex is back in her life.

Hondo and the SWAT team race to save Buck, their former unit leader, when he goes off grid and they fear he plans to harm himself. Flashbacks reveal the search for Buck, which coincides with one of the team’s most brutal missions, as each team member receives counseling and discusses the untold mental and emotional difficulties inherent to working in SWAT.

After the shocking shooting of a member of 20-Squad, Hondo and the team launch a citywide manhunt for the robbery crew responsible. Meanwhile, Deacon's plans for his future hit a snag, and Powell and Alfaro clash over a tricky issue.

SWAT faces their deadliest adversary yet when a violent cell of extremists looks to extract vengeance by blowing up half of Los Angeles, potentially killing thousands.

When a spree of brutal stash house robberies spills into L.A., 20-Squad must team up with the sheriff's department's gang unit to unmask a violent crew who leaves no witness alive.

When Hondo learns there’s a $1 million bounty on his head, 20-Squad must race to uncover the mysterious enemy from Hondo’s past who’s intent on revenge. Also, Deacon and Tan butt heads over Tan’s changes to S.W.A.T. academy.

The abduction of Luca and Street’s neighbor sends the SWAT team in pursuit of a home invasion crew targeting domestic workers to gain entry into upscale homes. Also, the SWAT division prepares to help Mumford mark a major career milestone.

Deacon’s family gets caught in the crosshairs of a drug cartel when he and the SWAT team aim to bring down its leader, a former foreign rebel force leader running drugs in plain sight via a local flower market. Also, Hondo receives troubling news regarding his father, and Tan is forced to go before an internal review board due to his girlfriend’s indiscretion.

Hondo and the SWAT team rally to support Street when he puts his life on the line to help his foster brother Nate break away from a drug ring.

When control of a university chemistry lab is seized, the team races to thwart a devastating terror attack.

The team works with the DEA and their iron-jawed leader, Mack Boyle, to stop a ruthless cartel boss waging war on the streets of Los Angeles as he exacts revenge on those who killed his son.

The SWAT team faces off with a family of doomsday preppers barricaded inside their fortress of a home, and Deacon finds himself at the center of the storm. Also, Tan clashes with a reporter covering the situation and Powell grapples with meeting the child she gave up for adoption 18 years ago.

As 20-Squad scrambles to track down a cold-blooded sniper terrorizing Los Angeles, Hondo discovers a link to his own South L.A. neighborhood that brings a personal twist to the hunt for the deadly shooter. Meanwhile, Tan finds himself questioning his leadership abilities while Powell and Alfaro compete in a classic game of SWAT tag.

SWAT tackles a mission with personal ties for Hondo when they race to find a group of missing students and their bus driver, Hondo's former high school football coach. Also, Hicks has reservations regarding Hondo's new 20-Squad team addition, Devin Gamble, a cop with a family background deeply entrenched in crime.

The squad races to find a missing child who was abducted from her front yard; Hicks is faced with a difficult decision concerning Gamble.

When three of L.A.'s finest are targeted and gunned down in the street, the team enlist the help of an LAPD psychologist to stop a murderous rampage, reopening old wounds tied to the department's failed response to a school shooting.

When a violent shooting rocks a Los Angeles nightclub, Hondo and 20-Squad are thrust into the dark world of sex trafficking, going head-to-head with a notorious biker club as they race to find a missing girl.

Hondo and Lina go undercover to infiltrate and take back a cruise ship that’s under siege by drug smugglers who will execute passengers if they detect police on board. Street enters the SWAT Training Academy and finds the competition fiercer than he expected.

The SWAT team sets out to recover dozens of DNA evidence kits stolen from an LAPD crime lab and bring in the crew responsible, after a close friend of Hicks is harmed during the theft. Financial strain at home makes it difficult for Deacon to focus on his role as leader of the SWAT division’s annual holiday toy drive.

The SWAT team finds itself under internal investigation after a civilian is killed as they attempted to bring in the city’s most wanted criminal. As the mission details are revealed, the force’s internal affairs team calls Hondo’s leadership into question.

The SWAT team searches for a group of drug smugglers who crash a plane in a Los Angeles suburb and scatter, after a joint mission with the DEA to stop the shipment goes awry. Also, Hondo tries to make amends with Nichelle, Luca experiences anxiety about his return to the field, and Deacon hesitates when asked to speak to a group of recruits about mental health.