Jebediah Owen stepped off the steamboat that brought him to the headwaters of the Missouri and onto the vast, unknown plains of the prairies. He was not heard of again. His betrothed—Susannah St. George—has gotten tired of waiting and takes matters into her own hands. Eliciting the aid of a French fur scout and incorrigible bigamist by the name of Jean Gallant, the two of them set out for the place where Jed told Susannah he could be found … where the river runs.