Cartel vengeance in Oregon's Lake County plagues Sheriff Henry "Bud" Blair until his friends plan war against the Ortegas in the Mexican state of Sonora in an effort to keep Bud safe from reprisals. In a surprising turn of events, a rival cartel tries to make sure Bud's friends leave Mexican affairs to Mexicans.

Back at home, Bud has his own hands full. Mariah's Song also takes the reader into the desperate world of drug addition. When street-wise, thirteen-year-old Mariahfinds her mother passed out on the living room couch, she says "Babs, you're gonna get high once too often." And when she sees Manny, her mother's live-in boyfriend trying to beat a man to death, her involuntary shout earns her a threat that sends her running for her life. Her flight takes her to the High Desert where an Amber Alert leads Sheriff Blair and his deputies on a desperate search to find Mariah before Manny does.