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 before anyone else is killed. Meanwhile, Hondo and Nichelle return home to find their house trashed, placing them at odds when it's revealed that Nichelle has a secret. And when Hicks, Mumford and Buck take a trip down memory lane, it threatens to end their decades-long friendships.

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. Still reeling from the anger and outrage directed at him by his own community, Hondo questions if he still has what it takes to lead 20-Squad, adding to the fear that he won't be able to pull the team together in time to save the city.