One of Perry Mason's trademarks is his ability, in court, to switch the physical evidence in a case. He generally does this with guns or bullets, and it confuses the jury, to his client's advantage. In this case, Perry offers a coroner's inquest two parrots, one of which swore like a muleskinner and was found near the body of a millionaire hermit who had been murdered.

After con man Greg Moxley married Rhoda Lorton, he took her money and flew, only to have his plane crash. Years later, Rhoda weds millionaire scion Carl Montaine. But now Moxley has turned up alive and well, with plans to pocket the Montaine fortune...or else make Rhoda's bigamy public.

After her wealthy Aunt Sarah is caught shoplifting, Virginia Trent suspects kleptomania. Some valuable diamonds left in Sarah's care go missing and Virginia turns to Perry Mason. When the gem dealer is murdered however and Sarah is seen running from the crime scene, the old lady becomes the chief suspect.