In the wake of a horrific civil war, El Salvador found itself confronted with enormously pervasive, deadly gang activity -- it seemed the official law enforcement channels were often incapable of fighting back against the flood of crime. Until, that is, a new organization came out of the shadows -- unaccountable to authorities, unstoppable, and brutal. Today's question: What is La Sombra Negra? They don’t want you to read our book. They don’t want you to see us on tour.