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 SWAT team searches for thieves who are on the run with a high-tech thermal lance that can cut through almost anything. To find the thieves, SWAT works to identify their target. Also, Chris confronts an imbalance in her relationship with Kira and Ty.