Deranged scientist Gustave Niemann (Boris Karloff), escapes from prison and overtakes the director of a traveling chamber of horrors. Pulling the stake out of a skeleton, he revives the infamous Count Dracula (John Carradine) and commands him to kill the man responsible for his imprisonment. He then finds the frozen Frankenstein Monster (Glenn Strange) and the Wolf Man (Lon Chaney, Jr.) buried under the ruins of the infamous Frankenstein laboratory. When he brings them back to life, the Monster is uncontrollable and drags him to a watery grave.