 When Dr. Frankenstein is killed by a monster he created, his daughter and his lab assistant Marshall continue his experiments. The two fall in love and attempt to transplant Marshall s brain in to the muscular body of a retarded servant Stephen, in order to prolong the aging Marshall s life. Meanwhile, the first monster seeks revenge on the grave robbers who sold the body parts used in its creation to Dr. Frankenstein. Soon it comes after Marshall and the doctor s daughter.