Walsingham Van Dorn has a fancy name but no money until he inherits 40 million dollars from a pair of wealthy, but wicked, uncles.

During World War I, a professional thief known as The Lone Wolf is assigned to steal a cylinder with important information from behind the German lines and bring it to Allied intelligence headquarters. However, German agents set out to stop him, headed by the man who was responsible for the death of the thief's sister.

John Stuart Webster, mining engineer, having accumulated a fortune in Death Valley, Calif., starts for Denver. On the train is Dolores Ruey, a beautiful Spanish girl reared in the United States. Webster thrashes a travelling salesman who has been forcing his attentions on Dolores and thereby gains her admiration. Upon his arrival in Denver he leaves for Sobrante, Central America, to finance a mine found by his former protege, Billy Geary. Dolores is also bound for Sobrante. Her father, Don Ricardo Ruey, had been President of the Republic, until he was killed by revolutionists. They board the same train but Webster is seized with ptomaine poisoning and is removed to a hospital. Dolores is met by Billy Geary, who falls desperately in love with her. When he arrives. Webster does everything to give Geary a clear field, but after he has put Dolores' brother in the place his father held, he finds he has not only won a revolution, but a wife.

Posing as a nobleman, Allan Harrowby takes out a policy with Lloyd's to insure that his upcoming marriage will occur, Dick Minot, Lloyd's assistant manager in the U. S., travels to San Marcos, Florida to handle anything that threatens to disrupt the wedding. On the train, Dick falls in love with Cynthia Meyrick, then discovers she is Harrowby's bride-to-be, he subdues his feelings.

When her drunken father dies from falling downstairs on the night of her engagement announcement, Helen Winthrop finds a note from him warning that drinking has ruined the family's past four generations. She breaks her engagement to lawyer Robert Craig so that she can test herself as she fears that her children might inherit the habit. After sacrificing her reputation to save that of her adulterous married friend Stella Scarr, Helen goes to a resort hotel where she wins a tennis tournament and flirts with Percy Farwell, the son of social climber Mrs. Honorah Farwell. In order to break up her son's romance with a supposedly disgraced woman, Mrs. Farwell hires Robert Craig.