Edward Van Sloan steps out on the stage to deliver a message to the audience, warning them that the movie may shock or horrify them, and they might want to leave.

In a village in Bavaria, Henry Frankenstein (Colin Clive) and his hunchback assistant Fritz (Dwight Frye) are piecing together a body from parts of freshly buried corpses and hanged criminals. Inside his watchtower laboratory, he intends to harness the lightning to give it life. But he still needs a brain. At a school nearby, Henry’s former teacher, Doctor Waldman (Edward Van Sloan) shows his class the brain of an average human being and that of a criminal. Later, henry sends Fritz to steal the healthy brain, but Fritz accidentally damages it, so he takes the other one.

Henry’s fiancée, Elizabeth Lavenza (Mae Clarke), speaks to their friend Victor Moritz (John Boles) about the secluded and unsocial scientist. Elizabeth and Victor ask Doctor Waldman for his opinion, and the doctor reveals that Henry wants above all things to create life. Concerned, they arrive at the lab just as he finishes preparing for his experiment. A lifeless body lies on a table as the storm rages outside, and he invites his guests to observe. Henry and Fritz raise the table to an opening at the top of the tower. Lightning strikes and the creature (Boris Karloff) is alive. It’s alive!

Despite it’s imposing size and grotesque form, the monster behaves like an innocent child. It sits when invited, it reaches out for sunlight, and it is frightened by Fritz’s flaming torch. They believe it is attacking them and they chain it in the dungeon, where Fritz enjoys threatening it with the torch. Henry and Waldman rush to the dungeon upon hearing a shriek and find that the monster has strangled and hung Fritz. It lunges at them and they lock it inside. Henry prepares a potion to destroy it and it falls unconscious.

Henry collapses, exhausted, and is taken home by Elizabeth and Henry’s father, Baron Frankenstein (Frederick Kerr). While Henry recuperates and prepares for his wedding to Elizabeth, Waldman examines the monster and prepares for vivisection. The monster strangles him, escapes from the tower, and wanders through the forested landscape. He meets Maria (Marilyn Harris), the young daughter of a farmer. They play a game, throwing flowers in the lake. Delighted, the monster throws Maria into the lake when they run out of flowers, and she drowns. Confused and horrified, the monster runs away.

Henry and Elizabeth are happily waiting for Doctor Waldman to arrive so they can marry. Victor rushes in and tells them that Waldman has been strangled. Henry suspects the monster. Later, it enters Elizabeth’s room and she screams. She is found unconscious and the townspeople search for the monster. Maria’s father appears, holding the body of little Maria. During the search, Henry is attacked by the monster and knocked unconscious. It carries him to an old mill. The peasants hear his cries and see that the monster has climbed to the top, dragging Henry with him, then hurls him to the ground. He is alive and the villagers bring him home while the rest of the mob set the windmill on fire, with the monster trapped inside. At Castle Frankenstein, Henry’s father toasts his future grandchild.

The film was directed by James Whale and produced by Carl Laemmle Jr., from a 1927 play by Peggy Webling, based on Mary Shelley’s 1818 novel Frankenstein, or the Modern Prometheus. It was adapted and written by John L. Balderston, Frances Edward Faragoh, Garret Fort, Robert Florey, and John Russell. It was produced and distributed by Universal Pictures and was a great success immediately, growing even more iconic over the years. The makeup by Jack Pierce is a triumph.

In 1930, Universal Studios was hemorrhaging money, losing more than two million dollars. Dracula opened at New York’s Roxy Theater in 1931 and made $ 700,000 profit. The studio turned to horror pictures in a big way. Bela Lugosi had hoped to play Frankenstein, but he was offered the monster, which was a killing machine without the pathos of Mary Shelley’s creature, and he refused. The first director, Robert Florey, was let go and replaced by James Whale. The brilliant electrical effects were designed by Kenneth Strickfaden, using a Tesla Coil built by Nikola Tesla himself.

The drowning scene was cut in four states, along with some of Frankenstein’s blasphemous outbursts. Kansas would have cut out half the movie. Some of this material was never recovered. The film was banned in Northern Ireland, Quebec, Sweden, Italy, Czechoslovakia, and China. The production was worried that the seven-year-old Marilyn Harris would be frightened by Karloff in makeup, but she ran up to him and asked if she could ride in the car with him to the scene location. He said, “Would you, Darling?” Throughout the scene, he wiggled his pinky finger at her out of view of the camera.

A poster of Karloff threatening Mae Clarke may be the most valuable poster in the world. His boots were called Hot Asphalt Boots and resist heat. They weighed thirteen pounds each. His costume weighed 48 pounds and made him eighteen inches taller and 65 pounds heavier. Those are not bolts in his neck, but electrodes. His back never recovered from the shoot and bothered him all his life. They put a microphone in the coffin to enhance the sound of the dirt hitting the wood. When Mel Brooks made his brilliant spoof Young Frankenstein, he discovered Ken Strickfaden’s electrical gadgets in the man’s garage and borrowed all of it. Dwight Frye (Fritz) had played Renfield in Dracula.