Book excerpt: A customs agent must track down a killer on a train barreling across the Texas border into Mexico . . . When a train leaves Laredo en route to Mexico City, the trip turns terrifying as one passenger after another falls victim to murder. Will anyone make it to their destination alive? Fortunately, Hugh Rennert—US Customs agent and amateur detective—is on board, and his investigation will proceed full steam ahead . . . “You won’t go wrong in giving Todd Downing a try.” —Michael Dirda, The Washington Post