As 20-Squad scrambles to track down a cold-blooded sniper terrorizing Los Angeles, Hondo discovers a link to his own South L.A. neighborhood that brings a personal twist to the hunt for the deadly shooter. Meanwhile, Tan finds himself questioning his leadership abilities while Powell and Alfaro compete in a classic game of SWAT tag.

When a crew of violent eco-terrorists abducts the teenage son of an energy company executive, SWAT must untangle the kidnappers' twisted motives before carrying out a high-stakes rescue mission. Meanwhile, Hondo's involvement in a shooting draws outrage from the very community he's dedicated his career to protecting. And, as Deacon is called on to help with the escalating crisis, he's forced to confront nagging doubts about his retirement.