Wages of Sin — Mark Wheaton

Not a day goes by that Father Luis Chavez isn't haunted by the cold-blooded slaying of his brother, Nicolas. But as the years pass and the case remains unsolved, there looks to be no end to his torment.

When Chief Deputy District Attorney Michael Story discovers a possible link between a murdered prosecutor and Nicolas's death several years before, the priest investigates, uncovering an international money-laundering scheme tying American banks to Mexican cartels. Finding himself the target of a brutal cartel hit squad, Father Chavez heads to Mexico, where he unearths a long-buried secret that pushes his faith to the breaking point.

As he fights to stop a seemingly endless cycle of killing, Father Chavez closes in on his brother's murderer, learning that sometimes the most incipient evil is found closest to home.