It took four novels for Steve Hockensmith to steer his sleuthing ranch hand brothers, Gustav “Old Red” and Otto “Big Red” Amlingmeyer, to Texas, but the budding town of San Marcos circa 1893 proves a fine fit for The Crack in the Lens and its unpretentious brand of mystery. The series was launched in 2006 with Holmes on the Range, in which Otto passes the time on a trail ride by reading a Sherlock Holmes story to the illiterate Gus, who decides to emulate the great man and solve crimes through deductive reasoning. Having displayed a surprising knack for “detectiving,” the saddle-bum Sherlock has now ridden off, Otto in tow, to the Lucky Seven ranch, in the Hill Country, where he is determined to unravel a heinous crime with a deeply personal connection: the brutal murder five years earlier of his darling Gertie Eichelberger. Deflecting nonstop threats from a series of rough characters with knuckles, guns, knives, and nooses, the brothers proceed with a suitably Holmes-ian investigation that is seasoned with a goodly serving of laughs. Hockensmith has ginned up a likable and compelling team, and he might do well to send the Amlingmeyers to the Capitol dome a few miles north to see what evildoers there require their attentions. Minotaur, $24.95