The Power of the Dog by Don Winslow — The first book in this trilogy, essential for understanding Keller and Barrera's relationship and the broader narrative arc.
Traffic by Tom Clancy and Steve Pieczenik — Explores the drug war from multiple perspectives with similar scope and political complexity, though less literary in approach.
The Sicario by Arthur C. Clarke — Features similar themes of corruption and violence in the drug trade with morally ambiguous protagonists navigating dangerous territories.