Esbeth Walters, a retired high school math teacher in her youthful 70s, tells herself that she's never too old to learn something new the hard way when she takes a job as part-time dispatcher at the Sheriff's Department - just a week after the mayor of a small town in the county has been murdered. New to the area, she soon learns that somewhere under the crust of her newly adopted rural Texas county there is a history of feuds, corruption, betrayal, and violence. Wild talk of a lost diamond mine helps to peel back the scab and she begins to wonder if even Texas Ranger Tillis Macrory isn't as tainted as the rest of them. He is overly friendly to attractive deputy Gala and has sat at the card table of gambler Morgan Lane. Esbeth tells him, "I think there's something about this one you needed, something that rattles you to your deeps." Tillis isn't helped when the murdered mayor's son Donnie and his girlfriend, Karyn, find another body - Denny's brother Hugh, who's been missing for forty years. Donnie and Karyn, daughter of Tillis' game warden friend, Logan Rainey, can't seem to leave the mess alone, and their relentless digging unearths a side to the story no one, not even Esbeth, could have expected.