The movie takes place in 19th century Germany, with the infamous Dr. Victor Frankenstein operating under the alias of Baron Frankenstein. The movie begins with Frankenstein approaching a young couple, Anna and Karl, blackmailing them to assist in his experiments involving the freezing of brains in a process called cryogenics.
During the course of his experiments, Frankenstein discovers that a former colleague of his, Dr. Frederick Brandt, had discovered a way to transplant brains from one body to another without the brain deteriorating. Frankenstein decides to abduct a patient from an insane asylum to use in his experiments, taking the patient to his laboratory for the transplant.
However, during the transportation, the patient dies, leaving Frankenstein and his assistant, Dr. Hertz, with only the brain to transplant. They decide to use a recently deceased body to complete the experiment. The newly created creature is tormented by the trapped soul of the patient whose brain was transplanted into the body, leading to violent outbursts and rebellion against his creator, Frankenstein.
Determined to rid himself of the monster, Frankenstein seeks the help of Anna and Karl, using their love for each other as a bargaining tool. However, his plan backfires when the creature discovers the truth and seeks revenge against his creator, leading to a climactic final showdown.
The movie explores themes of morality, revenge, and the dangers of unchecked ambition, as Frankenstein's obsession with his experiments leads to disastrous consequences for all involved.