It is a time of social unrest in the village of Frankenstein. The residents feel they are under a curse and blame all their troubles on the Frankenstein Monster. Rumors circulate about Ygor who is still alive and supposedly trying to revive the Monster. The villagers pressure the Mayor into allowing them to destroy Frankenstein’s castle. Ygor (Béla Lugosi) attempts to put up some resistance but the villagers rush the gates and begin to destroy the castle. Ygor, fleeing through the catacombs, finds the Monster released from his sulfuric tomb by the explosions. The exposure to the sulfur weakened the Monster but also preserved him. Unseen by the villagers, Ygor and the Monster flee the castle to the surrounding countryside. There they encounter a powerful thunderstorm. The Monster is struck by a bolt of lightning, but instead of being harmed by it, he seems to be rejuvenated. Ygor decides to find Ludwig, the second son of Frankenstein, to help the Monster.