After a domestic bomber dies in a Highland Park explosion, the SWAT team races to find the man's partner before more devices detonate. Also, Hondo reaches out to Buck, his former team leader, when he worries he is isolating himself after his recent firing.

Hondo’s life and career are endangered when his bosses and his godson’s kidnapper, Jae Kim, discover he’s been secretly surveilling Kim with the help of retired DEA agent Katrina Walsh. Also, Street and his newly paroled mother, Karen, both have trouble acclimating to her prison release.

The SWAT team hunts for a band of criminals re-enacting the crimes of the infamous Symbionese Liberation Army. Seeking expertise on the original crime spree in the 1970s, Luca and his father review the files of Luca’s late grandfather who worked for SWAT during the era of the original crimes. Hondo experiences discrimination from a fellow officer during a SWAT training seminar for local law enforcement in Arizona.

The SWAT team tries to zero in on the next target of a carjacking ring that’s using deadly force to boost luxury vehicles all over Los Angeles. Also, Hondo takes a big step to help his childhood friend’s incarcerated son, Darryl, and SWAT team leader Mumford weighs a major decision.

Lt. Lynch pulls the SWAT team’s focus when the mayor tasks her with enacting a departmental review of the squad right as they pursue the unstable and dangerous fugitive leader of an infamous doomsday cult. Meanwhile, Luca asks the team to invest in his new passion project, a Guatemalan food truck.

Deacon’s second job working private security at a high-profile boxing match places the SWAT team in the middle of a kidnapping case when a prize fighter’s wife is abducted. Also, Hondo’s young charge, Darryl, becomes frustrated with his lack of paternal rights regarding his infant son, and Tan prepares to introduce his critical mother to his girlfriend, Bonnie.

The SWAT team acts as a domestic surveillance unit for the CIA to confirm whether an international crime lord has resurfaced in Los Angeles after being off-grid for years. Also, Tan’s mother, Chan Fei, is a victim of racial discrimination, and Hondo encounters his ex-girlfriend Nichelle, for the first time since their breakup.

Hondo, Deacon and Tan team up with Thailand’s elite S.W.A.T. team to stop a ruthless drug lord whose heroin operation has far-reaching ties to Los Angeles.

When a convicted killer makes a prison break, the team works to protect the people on his hit list; Hondo unexpectedly crosses paths with an old flame.