The drug war has claimed thousands of lives in Mexico and now the violence has crossed the border into the United States. Nearly 40,000 people have already lost their lives south of the border, and now the cartels have moved their operations north and into our cities. Having followed Mexico's cartels for years, security expert Sylvia Longmire takes us deep into the heart of their world to witness a dangerous underground where people will do whatever it takes to deliver drugs to willing American consumers, including using armies of submarines that transport narcotics along the Central American coast, a network of secret tunnels used to smuggle tons of illegal drugs north, a no-fail system of transporting high-powered assault weapons south, marijuana farms inside our national parks, and meth houses in the Midwest. Drawing on her vast expertise in national security, Longmire offers real solutions to the critical problems facing Mexico and the United States, including programs to deter youths in Mexico from joining the cartels and changes that should be made to drug laws on both sides of the border. This is an important look at how Mexico's drug wars are compromising our national security, and a pressing call to rethink our relationship with our southern neighbor.