Law school graduate Paul Maddox, adopted son of Senator Robert Maddox, accepts an offer to join the law firm of William "Bill" Mellon, brilliant but unscrupulous criminal attorney. Mrs. Maddox is actually Paul's real mother, although neither the Senator nor Paul know it, and Bill Mellon is his father. Yes, it is one of "those" plots. Paul is at first critical of Mellon's sharp practices, but he relents when Ann McItyre convinces him it's all within the law, a fact most law school graduates would have learned in law school. Gambler Georgie Evans comes to Mellon and tells him he has just killed Harrison, another underworld character, and insists it was in self defense. Mellon coaches Evans in how to tell his story to the police, then sends him to police headquarters to give himself up, and then assigns Paul to follow up on the case. While Evans and Paul are on separate routes to the police station, Evans stops by Harrison's and kills him under circumstances corresponding with Mellon's fool-proof alibi version already supplied before the act. Truly a good example of why it is best to consult an attorney before committing a rash act. Mellon learns of this post-dated action but, for a large sum of money from Evans, agrees to have his firm represent him and assigns Paul the task. Paul, of course, wins Evans an acquittal. Paul later learns that the killing was committed after Evans had retained Mellon and quits the firm. Paul's moral snit does not extend past the point of allowing his adopted-father's influence getting him appointed Assistant District Attorney. Paul begins a probe against malpractice in the law profession, and Mellon hires Mitchell to dig up scandal on state officials sponsoring the probe. Mitchell does this even better than Mellon anticipated, especially when he comes back with the truth about Paul actually being Mrs. Maddox' own son. When Mitchell refuses to give up the papers with the proof, he and Mellon struggle and Mitchell dies from a shot from his own gun. Mellon is charged with murder and Paul is the prosecutor. Will Paul send his real Pa to jail for life?