Operetta set in New Orleans circa 1780. Marietta is there to escape from an unwanted marriage in France and Capt. Dick is there to lead his Rangers against a pirate gang. Marietta is first attracted to the son of the lieutenant govenor. But when he is revealed as the pirate leader, she turns her attentions to Capt. Dick. She decides he is the man for her when he is able to finish the ""Dream"" melody that Marietta recalls from childhood.