Carolina, an aging local grande dame who works at a crossing point on the titular river, marries another late-in-life character, the dredging-boat operator Antonio. Not long after their union, she becomes intensely jealous of Antonio's fondness for their winsome goddaughter, Joana, and insinuates herself into a relationship brewing between Joana and a mystical gypsy gold salesman. Soon, tempers are flaring, mystical secrets are being revealed and death is hovering over the central characters.