Book excerpt: Perfect for fans of Mick Herron and John Le Carré "The most important thing that's happened in Mexican literature in the last thirty years" Gaby Wood, Sunday Telegraph. It's Christmas in Culiacán and Detective Edgar "Lefty" Mendieta can't believe his luck. An old flame has returned with a teenage son he knew nothing about. Happiness seems to finally beckon for our careworn hero. The only snag is that Jason Mendieta wants to follow in his father's footsteps-even as Mexico's drug war descends a slippery slope toward chaos. While Lefty pursues a lunatic who has taken to bumping off dentists with a heavy-calibre pistol, a secret agent infiltrates a meeting of the drug lords and hears Pacific Cartel boss Samantha Valdés implore her underlings to stay out of the war. But an audacious murder provokes Samantha to change her mind and launch a wave of grisly killings across the country. Samantha then persuades Lefty to help her find the killer that pushed her over the edge. The truth he discovers will underline an old adage: revenge is a dish best served cold. No quiet family Christmas for our detective.