Philadelphia (Delie) Gordon, with her husband Brenton cruelly incapacitated by a stroke, continues to defy tradition by becoming first mate and skipper of the paddle steamer Philadelphia. Rising to this new challenge, Delie is happy with her activity-filled days, and with a growing awareness of the beauty of the river and its slowly paced life, she begins to find some contentment. However, Delie, though espousing the equality of the sexes, is all woman and is to be sorely tempted by the men who enter her life.
She engages in an affair with the debonair Alastaire Raeburn and whilst spending a romantic week with him, Brenton succumbs to a further stroke and dies. Consumed with guilt, this is to be Delie's darkest hour and she must once again gather all her strength in overcoming this further tragedy in her life.