Scientist Henry Frankenstein (Colin Clive) and his hunchbacked assistant, Fritz (Dwight Frye), embark on an unholy mission by stealing a body from a graveyard and a human brain from a medical college. Unbeknownst to Frankenstein, however, Fritz takes a violent and murderous abnormal brain. Henry's strange letters about his experiments worry his fiancée, Elizabeth (Mae Clark), and friends Victor (John Boles) and Dr. Waldman (Edward Van Sloan). They arrive at Frankenstein's laboratory to find the spectacular scene of creation under way--and Frankenstein intoxicated with his own godlike power.