In the movie, Dr. Cortner is obsessed with his research on transplanting human body parts, and he will stop at nothing to succeed in his experiments. After his fiancée's death, he manages to keep her head alive using secret procedures he developed in his lab.
Desperate to find a new body for Jan's head, he secretly ventures into the seedy underworld of local strip joints and nightclubs, where he searches for women who may be suitable for transplant surgery. But the more he tries to find the perfect body for Jan, the more he realizes how twisted and unethical his experiments have become.
Meanwhile, Jan's consciousness begins to awaken in her severed head, and she communicates with Dr. Cortner psychically, pleading with him to end her suffering and let her die.
As the experiments become more and more horrifying, the doctor's assistant, Kurt, grows increasingly disturbed by his boss's actions. Eventually, Kurt rebels against Dr. Cortner, sabotaging his experiments and trying to rescue Jan's head from the lab.
The Brain That Wouldn't Die is a classic B-movie horror film from 1962, known for its campy dialogue, over-the-top acting, and extreme gore. It has since become a cult classic among fans of the horror genre.