An innocent man is put on trial, but is he really as innocent as he claims? Diplomat David Talbot (William Powell) and his bride Lucienne (Hedy Lamarr) are enjoying a honeymoon in Paris when David is confronted by extortionists who demand money in exchange for not turning him in to the police. David has no idea what the men are talking about and ignores their threats, but the men prove good to their word, and David finds himself on trial for a series of thefts. At the trial, David's name is cleared when Henri Sarrow (Basil Rathbone) testifies that he knew the man who committed the crimes, a friend of his who recently died. However, after the trial, David meets Sarrow, who informs David that he lied under oath; according to Sarrow, David did indeed commit the robberies while suffering from amnesia after a severe blow to the head, and if he wants to keep the facts quiet, he'll do whatever Sarrow says.