Wealthy, crooked junk dealer Harry Brock arrives in Washington, D.C. with his brassy mistress, former Brooklyn showgirl Billie Dawn, and checks into a lavish hotel suite. Although he himself is crude and pushy, Billie's unrefined behavior embarrasses Harry during a meeting with Congressman Norval Hedges and his wife, and although he does love her, he considers breaking off their relationship until his lawyer, the alcoholic Jim Devery, reminds him that for tax purposes, he put his business holdings in Billie's name. Jim suggests that Harry hire someone to smooth Billie's rough edges and then marry her, because a wife cannot testify against her husband. Harry offers the job to reporter Paul Verrall, who earlier attempted to interview him. Paul readily accepts, both because he is attracted to Billie and because he hopes to discover something about Harry's operations. Later, Paul delivers some books to Billie, instructing her to circle everything that she does not understand and look up the words in the dictionary. The following day, Paul takes Billie on a tour of the capital. Billie is excited by her lessons in U.S. history, and her simple, honest enthusiasm impresses Paul. Paul's advice helps Billie to reconcile with her father, who does not approve of her relationship with Harry. Paul's disdain for Harry causes Billie to raise questions about Harry's business dealings. One day, after eavesdropping on Harry's conversation with Jim and Hedges, Billie, who with Paul's encouragement has started to express herself, asks Hedges why he puts up with Harry's bullying and points out that Harry was never elected to a position of power. Then, when Jim asks Billie to sign some papers, she refuses to do so without first reading them. This so angers Harry that he hits her, and an hysterical Billie leaves the apartment. She contacts Paul, and the following day, believing Harry to be out, the two of them search Harry's room for the papers. Harry is home waiting, however, and while Billie distracts him, Paul takes the papers. Later, Harry proposes to Billie, who turns him down, explaining that she is leaving him in search of a different life. When Billie reveals that Paul has taken Harry's papers and plans to expose his nefarious dealings, Harry offers Paul money to return them. Paul is uninterested, however, and Billie offers to sign back one company a year to Harry as long as he behaves himself. Finally, Billie and Paul, who have each grown more like the other, get married.