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 goes in pursuit again of the militant group The Emancipators, when the criminals hold a live stream kangaroo court to publicly execute city politicians. Also, Hondo fights to lift Darryl’s spirits; Deacon feels unworthy as he prepares to receive one of the LAPD’s highest honors; and Street catches a break in the search for his missing parolee mother.

The SWAT team works with Lieutenant Piper Lynch, a senior LAPD Hollywood Division officer, when the mayor assigns her to oversee city departments joining forces to stop a serial bomber using drones as detonation devices. Also, just as Hondo settles into legal guardianship of his teen charge, Darryl, his home life becomes more complicated when his estranged father unexpectedly moves in.

The SWAT team bumps heads with Lt. Lynch when she signs them up for an off-book undercover operation to take down a local gang printing counterfeit money, without giving them enough time to prepare for the mission. Also, tensions rise at home for Hondo as his parents’ strained relationship becomes worse.

The Harrelsons engage in a tense family reunion when Hondo’s older sister, Winnie, begrudgingly arrives in Los Angeles to see their sick father for the first time in decades. Also, the SWAT team searches for an abducted Middle Eastern human rights activist; Luca’s food truck business hits a snag; and Street worries that dating Captain Hick’s daughter, Molly, will negatively impact his career.

The SWAT team searches for thieves who are on the run with a high-tech thermal lance that can cut through almost anything. To find the thieves, SWAT works to identify their target. Also, Chris confronts an imbalance in her relationship with Kira and Ty.

The SWAT team engages in tense negotiations with a family that takes a local officer hostage when they’re evicted from their home due to eminent domain. Also, Hondo reflects on his personal life choices as he helps his father through a medical crisis and Chris’ relationship with Kira and Ty reaches a critical juncture.

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.

Hondo, Deacon, Tan and Commander Hicks engage in a manhunt across Tokyo when they escort an extradited fugitive to Japan, where he escapes local custody. Back in Los Angeles, the rest of SWAT search for any contacts the criminal cultivated while hiding out in Los Angeles, and Street isolates himself from the team as he deals with family issues.

The SWAT team goes on the hunt for a sniper who is targeting the Los Angeles Fire Department by setting fires around the city to lure in unsuspecting engine companies. Also, the rivalry between Chris, Street and Tan ratchets up when Tan finds out there’s an internal betting pool on which of them will win the SWAT leadership competition. And, Street and Molly’s relationship is strained by his complicated history with his imprisoned mother.

A tragic mission leads each member of the SWAT team to contend with their emotional distress in varied ways.

As the SWAT team helps the LAPD search for the prime suspect in a woman’s disappearance, they’re joined in the field by a new team member. The personal strain between Chris and Street comes to a head as both await Hicks’ decision on who the winner is of a prestigious leadership competition.