Set during the 16th century tumult of exploration and first settlements along the Paran River in Argentina, River of Sorrows, based on actual events, is told by people marginalized and usually invisible in history. Mestizo soldier Blas de Acu a's great unrequited love for the firey Mar a Muratore prompts him to tell the story of Mar a's amazing exploits, but it's not Blas but his second wife who insures that Mar a is not forgotten by history...