S1·E7 Strange Currencies

Chase and August are eyewitnesses to a young man who throws a Molotov cocktail into a car right outside the gym. The perpetrator gets killed in the ensuing pursuit, but they find out that the car was registered to Carlos Altamarino, a known drug dealer. Chase is visited by an old college friend, now a CIA agent, who gives Chase a mysterious gold key for safekeeping and reveals that Carlos' operation has shifted power to a brother, a cousin, or perhaps even Carlos himself using an alias. The new boss carries the name Charlie Altamirano. Chase's friend is killed later, and the detectives work to figure out just what exactly is going on.