Boris Karloff, a gentle ex-convict on the road to reform, is framed by a group of gangsters led by corrupt attorney Ricardo Cortez for the murder of the judge who had sent him to prison. Though the evidence is mainly circumstantial, Karloff is convicted and sentenced to die in the
electric chair. Immediately after his execution, authorities learn that Karloff was innocent, so they allow scientist Edmund Gwenn to try bringing him back to life using the new "Lindbergh Heart." (This device was an actual mechanical circulating system developed by famed flier Charles A.
Lindbergh in cooperation with several physicians.) The experiment succeeds and Karloff lives again, t...