Hondo confronts his long-held resentment towards his ailing father, Daniel Harrelson, Sr., when he and his sister, Briana, try to convince their dad he’s no longer well enough to live alone. Also, when the SWAT team works as patrol officers for a day, Chris is partnered with Mumford, who intends to make her a surprising offer.

A fake 911 call puts Hondo and the SWAT team on the hunt to stop a white supremacy group from executing bombing attacks on local communities. Also, Street’s relationship with his recently paroled mother, Karen, jeopardizes his career, and Jessica is thrown a curveball by her colleague, Michael Plank, president of the police commission. Hondo’s father, returns Daniel Harrelson, Sr. 1st.

When the SWAT team is called in to work on their day off to end a hostage situation, they discover one of the captives is a wanted felon. When Hondo saves his sister after she's been roofied at a nightclub, he uses his day off to hunt a serial rapist.

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.

Street reconnects with his estranged foster brother, Nate, to help a joint investigation between SWAT and the Long Beach Police Department when criminals steal a mass arsenal of LAPD assault rifles. Also, Hondo finds himself at odds with his father over the elder man’s declining health, and Luca is overwhelmed when the entire team reconsiders becoming investors in his food truck,

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.