On Both Sides of the River paints a vignette of south Texas-its people, history, and cultural diversity-through interwoven tales of the scourge of drug-trafficking on both sides of the Rio Grande River and of the annual quest for the monster whitetail buck of Mexican and south Texas lore, El Cacaistón. Joe González, a south Texas criminal defense lawyer, finds himself embroiled in a situation involving drug-trafficking, corruption, and violence. He overhears young, violent American drug lord Mark Balbuena, heir to the Balbuena family ranch, talking to someone in a local bar about drug deal. When young Balbuena makes the massive deal with a notorious Mexican drug lord, an unexpected double-cross begins a drug war. Despite Mark's plan to save it, the Balbuena ranch is purchased by entrepreneur Max Wadsworth. Even so, to González, the presence of Mark Balbuena on the ranch clearly suggests he was trafficking drugs from the family ranch. Only time would reveal now whether the Balbuenas would emerge from the trouble unscathed, or whether it would all fall apart.