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.