For more than forty years, Art Keller has been on the front lines of America's longest conflict: the war on drugs.

His obsession with defeating the world's most powerful, wealthy, and lethal kingpin—the godfather of the Sinaloa cartel, Adan Barrera—has left him bloody and scarred, cost him the people he loved, even taken a piece of his soul. Now Keller is elevated to the highest ranks of the DEA, only to find that in destroying one monster he has created thirty more, who are wreaking even more chaos and suffering in his beloved Mexico. And not just there.

Barrera's legacy is the heroin epidemic scourging America. Throwing himself into the gap to stem the deadly flow, Keller fin