Lengthy, ambitious, and uncompromising, Don Winslow’s 16th novel is, as most crime fiction fans must know by now, a continuation of his 2005 novel The Power of the Dog. That earlier work introduced DEA agent Arturo “Art” Keller and his bête noir, Adan Barrera, a silky, villainous Sinaloan drug lord who is, according to Winslow, a fictionalized version of recent Mexican prison escapee Joaquín “El Chapo” Guzmán Loera. The Power of the Dog was written before Los Zetas, the military arm of the Gulf cartel, rose to the top of the drug-trafficking, kidnapping, oil- and gas-stealing, head-chopping gangs. The Cartel brings us up to date on the Zetas’ horrific crimes, but more important are its characters—primarily an older, even more depressed Keller, who at first sight is in retirement at a New Mexico monastery tending to bees, Sherlock Holmes-style, and a slightly mellowed Barrera, who, like his real-life counterpart, has effortlessly escaped his Mexican prison cell and gone back to business. But, unlike El Chapo, Barrera is more pragmatic than homicidal, with at least a self-deceptive sense of honor. There is a rich assortment of other carefully crafted players, among them a wild child Chicano, Chewy the Kid, traumatized and trained to kill from the age of 11; Magda Beltran, a beauty queen imprisoned for money laundering who winds up being Barrera’s jailhouse inamorata and eventually a top narco; Eddie Ruiz, a charming if shady small-time dealer from Texas who is caught up in the war between the Sinaloa and Gulf cartels and who turns amusingly heroic; and the horrific kill-crazy head Zeta, Heriberto Ochoa, somewhat based on Heriberto Lazcano Lazcano, the late torture-loving Zetas leader. Reader Ray Porter’s rendition of this bloodstained panorama is, at first, oddly removed, a professional, broadcast-voiced observer with no dog in the fight. But as the characters are introduced, he begins to mirror their moods and temperaments—matching Keller’s grim, sardonic attitude, for example, or Magda’s soft and effectively feminine voice as she brazenly moves up in the narco trade. He’s especially effective in his audio delineation of Chewy, a sad and confused child who kills and even flays on order but whom Keller and, one assumes, Winslow, does not see as a lost cause.