First, this film is way ahead of its time in foreshadowing heart transplants and (yet to be achieved) artificial hearts. The first act is all about the artificial heart thing. Act 2 is a courtroom drama about the doctor being sentenced to hang for an accidental killing of his medical student during the experiment. Act 3 is the revenge against the jurors and judge who convicted him. Each act of this melodrama is delicious but Act 3 is by far the best. My only gripe is that it ends too soon. It would have been more fun to have a few more gimmicks to revenge the conviction. This film reminds me of the classic "12 Angry Men" but is a lot more fun and to the point. Great production values for 1939.