
Daniel "Hondo" Harrelson, a Los Angeles S.W.A.T. lieutenant, is assigned to lead a highly skilled unit in the community where he grew up. Torn between loyalty to the streets, where the cops are sometimes the enemy, and allegiance to his brothers in blue, he strategically straddles the two worlds. Hondo encourages his team to rely on communication and respect over force and aggression, but when a crisis erupts, these unflinching men and women are prepared to put their tactical training to the test.

When two students are brutally attacked, 20-Squad contends with a possible honor killing; Hondo and Nichelle have their first parenting dispute while searching for a suitable daycare.

When back-to-back shootings at women's clinics leave two healthcare providers dead, Hondo and the team investigate whether the shootings were politically motivated.

When a spree of brutal stash house robberies spills into Los Angeles, the team joins with the sheriff's department's gang unit to unmask a violent crew who leaves no witness alive.

The team faces a prison hostage situation, only to be thrown into deeper danger when a bomb explodes, freeing maximum-security prisoners from their cells, including someone with a personal grudge against Hondo.