While commemorating the anniversary of her daughter's tragic drowning in a flash flood of the Río Grande, Francisca Warrior, a Black-Seminole veteran of the Gulf War, kills a militaman about to rape Rosario, a Mayan refugee from Guatemala who has just crossed the border. The murdered and the undocumented immigrant together flee the law, and Border Patrol agent Reylando Madrid, who seeks to apprehend them in hopes of reviving his moribund career. Reynaldo pursues Francisca and Rosario from the mouth to the source of the Río Grande, which, embodied by an actor, serves as narrator and portrays the other characters in the play.