Based on the career of William Fallon, a skillful prosecutor changes to defending criminals, but a young secretary awakens his conscience.
Vincent Day (Warren William) persuades a jury to execute a young man, but he learns from D. A. Forbes (Walter Walker) he is innocent. Forbes calls the prison, but it is too late. Day resigns. A bartender (Guy Kibbee) tells drinking Day he shouldn't just defend the innocent. Day cross-examines a boxer about being knocked out and then knocks him out to prove his point. Barton (John Wray) tells Day he embezzled $90,000 and shows him the $40,000 that is left. Day calls Smith (Morgan Wallace) to discuss it. Day complains about typing to Miss Hickey (Aline MacMahon) but keeps on young Celia (Sidney Fox). Day offers Smith $30,000 not to prosecute Barton. At the bail bonds office of J. B. (Ralph Ince) Garland (Jack La Rue) gives Day money. Smith asks D. A. Forbes to prosecute Day but gets nowhere.
Day invites Celia to lunch, but she has a date with John (William Janney). In court Day defends Tony (J. Carrol Naish) by drinking the incriminating poison. After the jury acquits Tony, Day gets his stomach pumped and celebrates at a party. Celia tells John that she loves him, but Day calls her to work at night. John complains about Day's tricks. Celia drinks brandy with Day, who practically proposes and tries to kiss her; but she resists and learns that he used a trick with the poison. Celia refuses to accept his blood money and quits, calling his life a lie; but she agrees to stay on a week or two.
On her last day Celia tells Day she is marrying John. Day gives her a check for $100 he earned writing a law article. Day gets drunk with women. Celia and Hickey look for Day. Hickey finds him passed out and gives him coffee. Hickey gets Day showered and shaved. Celia tells Day that John was arrested for taking bonds. Day calls J. B. to get John bailed out. John tells Day that he was held up on the street, but Day calls him a liar. Day learns that Garland pulled the bonds job. Day calls on Garland and asks him to give him the bonds; but Garland says no. Garland is arrested at the train station. Celia and John invite Day to their wedding. J. B. tells Day that he sprung Garland, and Day should come with him. Day warns J. B. that he has a file on the "boys" that will go to the D. A. if anything happens to him. Day tells Hickey that he is going back to civil practice. On the street Day is shot but gets in a cab, joined by Hickey. Day says the papers are in the vault and dies in her arms.
By dramatizing the dangers of a lawyer being too skillful in an adversarial system this true story shows how judicial mistakes can result in deadly consequences.