Lucas Davenport takes the scenic route toward a confrontation with the two practiced crooks who had the bad luck to rob him. Just as he's leaving an ATM with $500, the star of Minnesota's Bureau of Criminal Apprehension is held up by a pair of obvious meth users, a man and a woman. Naturally, Lucas vows vengeance. Before he can catch up with the pair, however, he and his team will have to wade through a thicket of unrelated violence visited on the Midwest by a trio of Mexican gunslingers. The hit men, whom Sandford (Buried Prey, 2011, etc.) inventively dubs Uno, Dos and Tres, first pop up on Lucas' radar when they torture and execute Patrick Brooks, founder of Sunnie Software, and his wife and children. A preliminary investigation ties the murders to a money-laundering operation that crosses the border, and the connection is strengthened when the Mexican government sends Inspector David Rivera and Sgt. Ana Martínez north as observers. They end up doing a lot more than observing because the three killers are just getting started. On orders from their mysterious boss, Big Voice, they're pursuing a fortune in gold that's gotten stuck halfway through the money-laundering chute and cauterizing any leaks among the system's conspirators while they're at it. Despite the high mortality rate, the procedural work is more grueling than fascinating, and the criminals are mostly as nondescript as their monikers. But the climactic gunfight is deeply satisfying, and the very last line of dialogue is perfect.