Disgusted when the police department fails to apprehend the murderer of her guardian, Henri Du Bois, Celeste decides to track down the criminal herself. Her only clue is a cuff link dropped near the scene of the crime on which a sphinx is engraved, and with it, she wanders through Paris' tough Moulin Noir district. When she notices a young man wearing a tie pin of identical design, she cultivates his acquaintance and eventually asks him to visit her in her home. His suspicious behavior there convinces Celeste that he is the guilty party, and although she has fallen in love with him, she has him arrested, whereupon she learns that he is Du Bois' missing son, Andre. Further detective work reveals that the real murderer is Celeste's rejected suitor, Raoul Laverne. Upon his confession, Andre is released and eventually marries Celeste.

Pat Dugan puts his last penny into oil prospecting and finds the oil. He deserts the old shack for his idea of what a palace should be and sends Jimmie to college. Jimmie promptly thrashes three of the students and polishes off the policeman who interferes. Then he leaves college for a partnership in a nursery business with a young Italian. Pat moves east and settles next door to Lady Blessington, but supposes the placid old lady who fraternizes with his wife to be the house- keeper. Jimmy turns up and falls in love with Joyce, Lady Blessington's god-daughter and marries her in spite of his father's commands, but when Pat sees how it all comes out he takes the full credit to himself.

Social worker John Warfield meets socialist radical Guido Garcia, and together they establish a refuge in San Francisco for life's unfortunates.