In Austin, Texas, thousands of artists and over a million fans flock to the "live music capital of the world" every year, and where there's live music and festivals, drugs are never far away. With so many potential customers, competition among sellers is fierce. The Sinaloa cartel uses a network of traffickers and runners to smuggle huge shipments of ice into Texas from Mexico, but the A.T.F. and Border Patrol are trying to cut it off.