Lou travels to El Salvador, home of the second highest murder rate in the world, to meet the 18th Street, a ruthless, multi-ethnic, transactional criminal organisation engaged in a bloody war with rival gang MS-13. To find out what motivates the on-going war, Lou realizes he will have to meet their feared and infamous leader, Viejo Lin, and journey to Izalco Prison in Sonsonate, El Salvador, which houses 838 of the country's most violent 18th Street gang members, including many of its feared inner circle.