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.

The SWAT team races to find a militant group that escaped their capture months earlier, when the criminals take hostages in exchange for a $500 million ransom from five corporations they deem corrupt. Also, Hondo’s emotional turmoil begins to affect his team leadership.

The SWAT team pursues a group of unknown assailants responsible for a patrol officer’s death before tension in the city between the police and the community explodes. Also, as Chris reels from the revelation that she knew the patrol officer who was killed, Deacon and his wife, Annie, prepare to welcome their newest child.

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.

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.

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 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.

Following a string of violent home robberies, the team rushes to stop a crew targeting elderly victims; Hondo's longtime friend and former Marine squad leader Danny Wright turns to Hondo for help when his daughter goes missing.

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.