The year is 1973. A four-man crew of stick-up artists has been on a rampage in South Texas along the Rio Grande corridor from El Paso to Laredo. One day they stick up the bank and liquor store in Mosby in Quayle County, killing one person and severely wounding another. Mosby is a small town in a large county, with only 3,000 souls and very little crime. Sheriff Solomon Pratt and his eight-man, two-woman department are committed to bringing the culprits to justice. Deputy Barlow Adams is doubly committed because one of the victims is his brother-in-law. Barlow's bond with his brother-in-law is thicker than blood.