When a spree of brutal stash house robberies spills into L.A., 20-Squad must team up with the sheriff's department's gang unit to unmask a violent crew who leaves no witness alive.

S.W.A.T.'s anti-terror sting operation at a bus station is thrown into chaos when felons, fleeing the police, burst in and take the bus station hostage; Bennett redoubles her efforts to force Hicks out as S.W.A.T.'s commander.

The SWAT team undertakes its final mission when a violent crew of ex-pat Russian mercenaries holds LA hostage after planting hundreds of explosives across the city.