Hondo and Hicks desperately search for Powell, who's gone missing in Mexico City along with a thermobaric bomb capable of killing thousands. Deacon's pride gets injured in a boxing match with Rocker.
20-Squad must leap into action when Yakuza assassins descend on L.A., targeting a number of mysterious Japanese ex-pats. Meanwhile, Nichelle finds her job on the line at the inspector general's office when a colleague accuses her of taking bribes.
SWAT hunts down a Chilean arms dealer after he kidnaps a woman and her daughter from a party in L.A. with unexpected intentions. Crossing paths with his brother, Tan is forced to come clean to his family about his divorce from Bonnie, while Hondo discovers that Hicks has received a job offer that could lure him away from SWAT.
While training with Long Beach SWAT, Street discovers a biker club has stolen a cache of armor-piercing bullets and brings 20-Squad into the hunt for the gang before they can pull off a daring and deadly heist. As Hondo struggles with changes at work, Nichelle finds herself at odds with her former colleague Bruce.
After a prison transport van overturns, Hondo and the team hunt down three female fugitives, including a serial killer on the verge of a rampage. Also, with Annie’s return to work, Deacon struggles to maintain a work life balance, and Luca does his best to teach Kelly to drive.
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.
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.
When a female robbery crew "honeytraps" and kills several rich VIPs, Hondo and 20-Squad are called in to assist FBI Agent Jackie Vasquez in capturing the dangerous fugitives before the death toll rises. Commander Hicks is shocked when his new love, Maggie, abruptly ends their relationship without rhyme or reason. With help from Deacon and Dr. Wendy, Hicks makes an important decision about his romantic future.
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.
Tan finds himself on a one-man mission to save his new love interest and her journalist co-workers when mercenaries take over a black-tie correspondents' dinner. After the group escapes, it's up to SWAT to track down the well-trained gunmen.
When a crew of violent eco-terrorists abducts the teenage son of an energy company executive, SWAT must untangle the kidnappers' twisted motives before carrying out a high-stakes rescue mission. Meanwhile, Hondo's involvement in a shooting draws outrage from the very community he's dedicated his career to protecting. And, as Deacon is called on to help with the escalating crisis, he's forced to confront nagging doubts about his retirement.
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.