Tom Stuart takes risks-- in war, in love, and in card games, from St. Louis to Mexico. And the hard-drinking, fast-talking steamboat captain-- who knows every shoal and eddy of the Rio Grande from the Big Bend to Brownsville-- has a dream of building a shipping empire that will span the windswept Gulf of Mexico to rich, exotic New Orleans. But this is a kind of gamble he's never faced before: with a woman to win, a woman to lose, and a dangerous man standing in the way. Now, Stuart is plunged into a fight that will engulf his very soul. And to the winner will go the mighty Rio Grande...