Working in his castle laboratory, Doctor “Charles” Frankenstein hoists a female subject toward an opening in the ceiling, attached to equipment that charges her with electricity. When she awakens, Frankenstein’s monster asks if she is to be his bride and the doctor agrees, before instantly changing his mind. The angry monster lashes out at Frankenstein, destroys the laboratory, and flees. Later, in a village, the monster meets a dwarf named Rinaldo, who invites the creature to join him on his way to a circus in Budapest, Hungary. Elsewhere, Doctor Frankenstein explains to his friend, Clerval, that his female “patient” may be incurable. He says she was discovered in the woods, suffering from amnesia after being struck by lightning. However, she has the mind of a child, so he can mold her into the “perfect” woman. Frankenstein christens her “Eva,” after Eve in the Bible. At the castle, Eva struggles to regain her speech. Meanwhile, Frankenstein’s monster and Rinaldo continue their journey, stealing from a church, and drinking at a pub. As they become friends, the monster shares his desire for Eva, and Rinaldo brands the nameless monster “Viktor,” explaining that it means, “he will win.” Showing Viktor a medallion around his neck, Rinaldo shares his dream of going to Venice, Italy. When they arrive in Budapest, Rinaldo secures circus jobs for Viktor and himself. Back at the castle, Eva’s health improves and Frankenstein continues her education. He dresses her in finery and presents her at a high society gathering. She impresses the attendees and catches the eye of a man named Josef, but when Eva sees a cat, she howls at the feline, and Doctor Frankenstein realizes she still has much to learn. Sometime later, Eva becomes suspicious over Frankenstein’s story because no one from her past life has come looking for her. Meanwhile, at the circus, Rinaldo performs as a trapeze artist. When he makes enemies with other performers, a man named Bela cuts his safety rope. Later, during a performance, the rope gives way and Rinaldo crashes to the ground. As he dies, Rinaldo gives Viktor his gold medallion that has the word “Venice” engraved on it. He tells Viktor to leave the circus and follow his heart. Learning that Bela is the murderer, Viktor kills the circus performer in revenge. Later, Eva comes upon Viktor sleeping in the woods. Taking pity on the monster, she offers him a gold coin and Viktor, hiding his true identity, gives her Rinaldo’s medallion. When Eva returns to the castle, Doctor Frankenstein sees the medallion and becomes jealous. In time, Eva and Doctor Frankenstein attend a masked ball. There, Eva sneaks away and kisses Josef as Frankenstein watches. Elsewhere, circus performers see Viktor in a village and chase after him as revenge for murdering Bela. He is caught and shackled in a prison. Later, Eva escapes the watchful eye of Frankenstein to meet Josef, but as they kiss, Frankenstein appears and strikes Josef, threatening his life. When Josef insists that Eva means nothing to him, she leaves, hurt. Back at the castle, Eva argues with Doctor Frankenstein, accusing him of fabricating the story of finding her in the woods with amnesia. He admits that he did, in fact, create her by sewing corpses together, and claims her as his bride. When Frankenstein shows Eva journals detailing that she was originally created as a mate for Viktor, she screams in terror. Frankenstein then falsely reports that Viktor is dead. They argue and Eva locks herself in her room. Sensing Eva’s fear, Viktor breaks free of his prison chains and races to her rescue. Eva looks at Viktor’s medallion and understands he is her intended groom. Doctor Frankenstein breaks through her door and assaults Eva as Viktor arrives. A fight ensues and Eva faints. While battling on the rooftop, Frankenstein falls to his death. Viktor returns to Eva’s side, and she awakens to his touch. She asks if he is aware that Frankenstein created him, and Viktor tells her that Frankenstein is dead. Eva expresses her desire to share the future with Viktor.