Bobbie Walters, a cab driver in a Midwest city who is trying to save enough money to marry his sweetheart, Dorothy Wright, an attendant at the cigar and newspaper counter of a large hotel, is able to amass $15,000. He acts like a millionaire and soon is fleeced of the money by two Wall Street swindlers. Broke, Bobbie is forced to work as a bellboy at Dorothy's hotel. After a series of struggles and adventures, Bobby wins a fortune in the oil fields of Louisiana, despite the efforts of his rivals, who dynamite his oil derricks.

Jack Duncan returns from the war in France to his wife and baby and learns that his job as a draftsman at the Loring Steel Mills has been taken. Given work in the machine shop, Jack becomes the prey of Red agitators who want him because of his popularity with soldiers. The Reds cause Jack's discharge just when his house payments come due, and when they convince him of the injustice of his situation, he joins their ranks. After learning of plans to burn the factory and Loring's home, and start a riot in the town, Jack is won over by a socialist's arguments advocating mild reforms. At a meeting of workingmen, Jack praises Americanism. He warns Loring and, with soldiers at a nearby camp, quells the riot. After a woman agitator kills her comrades and then shoots herself, Jack arrives home to save his wife from an attack by a Red ringleader. Jack is then made a foreman at the mill.

The film is based on a book of the same name by Arthur Guy Empey, detailing his service as an American volunteer with the British Army on the Western Front.