Ruth Carroll, a schoolteacher in New York's Lower East Side, meets Bolshevist Alexis Minski at her grandfather's bookstore. After Ruth complains to her superintendent about undernourished schoolchildren, Minski's ravings cause her suspension, and she joins the Reds. Meanwhile, Captain Nathan Levison, returning from the Argonne, is assigned by the Secret Service to investigate New York's radicals. While visiting the Carrolls to announce the imminent arrival of Ruth's brother Davy, who saved Levison's life but lost his foot, Levison falls in love with Ruth. Chagrined, Minski convinces Ruth that Levison plans to arrest her and her grandfather, whereupon Ruth furiously requests that Levison be killed. After Governor Alfred E. Smith signs a bill making it illegal to display the Red flag, the Bolshevists plot to assassinate him, the Mayor of Seattle, and Attorney General Alexander Palmer, but Davy, with other soldiers, break up the meeting.

Rev. Bradford seeks the health resort conducted by William Muldoon. "Kid Garvey," who has known Mr. Muldoon for many years, calls on his old friend. Rev. Bradford arrives and he chooses the "Kid" as his trainer, believing him to be one of the regular trainers of the institution. Garvey seeks an opportunity of breaking into "swell society" and requests that he be introduced by his right name, Frank Sheldon.