Marie Laurent, a young doctor, receives an offer to go to work in the laboratory of Professor Kern. The office in which Kern accepts her makes a very gloomy impression. But a visit to the laboratory turns out to be much more gloomy: there, Marie sees a human head separated from the body. The head is mounted on a square glass board, tubes go from it to various cylinders and cylinders. The head is strikingly reminiscent of Marie, the recently deceased Professor Dowell, a renowned surgeon. This is really his head. According to Kern, he was able to "resurrect" only the head of Dowell, who suffered from an incurable disease. (“I would prefer death to such a resurrection,” Marie Laurent responds to this.)
Marie goes to work in the Kern laboratory. Her responsibilities include monitoring the state of the head, which "hears, understands and can respond with facial expressions." In addition, Marie brings a lot of medical magazines to her head every day, and they “browse” them together. A semblance of communication is established between Marie’s head and Marie, and one day Professor Dowell’s head asks the girl to turn off the faucet on the pipe leading to his throat (Kern strictly forbade Marie to touch the faucet, saying that this would lead to the immediate death of her head). The head manages to explain to Marie: this will not happen. The girl hesitates, but in the end he fulfills the request and hears a hiss and a weak cracked voice - the head can speak! In secret conversations, Marie Laurent and the professor’s head find out the monstrous details of the revival.
Kern was an assistant professor. He is a talented surgeon. During their collaboration with Professor Dowell, an asthma attack occurred, and, waking up, he saw that he had lost his body. Kern needed to keep the professor’s brain active in order to continue his research. Dowell refused to cooperate with him, although Kern forced him to use the most brutal methods (passing an electric current through the professor’s head, mixing irritating substances with nutrient solutions). But when Kern, conducting experiments in front of his head, made several mistakes that could ruin the results of their efforts, Professor Dowell could not stand it and agreed to continue working.
With the help of Dowell, Kern revives two more heads, male and female (Tomas Bush, a worker who got caught in a car, and Briquet, a small girl from a bar who received a bullet that was not intended for her). The operation is successful, but the heads of Tom and Briquet, unlike Dowell, who are not used to intellectual activity, languish without a body. Marie Laurent is adding more work. She not only monitors the state of all three goals, but also shows Tom and Briquet films, includes music for them. But everything reminds them of their former life and only upsets them. Persistent Brika manages to persuade Kern to try to sew her a new body. In the meantime, Kern learns about Marie's conversations with Professor Dowell's head. The girl is ready to expose him, telling the whole world his terrible secret, and Kern forbids Marie to return home. Marie tries to protest. Kern, in front of her eyes, turns off one of the taps, depriving Dowell of air. Marie agrees to his terms, and the laboratory becomes her prison.
At the scene of the train accident, Kern finds a body suitable for Briquet and kidnaps him. Engraftment is successful. Soon Briquet is allowed to speak. She tries to sing, and a strange thing is revealed: in the upper case, Briquet’s voice is quite squeaky and not very pleasant, and in the lower case she has an excellent chest contralto. Marie scans the newspapers to see who owned this young, graceful body that Briquet now inherited. She caught the eye of a note that the corpse of the famous Italian artist Angelica Gai, who was following the train that crashed, disappeared without a trace. Brika is allowed to stand, she begins to walk, sometimes in her gestures an amazing grace is noticeable. Briquet is fighting with Kern: she wants to return home and appear in front of her friends in a new guise, but the surgeon does not intend to let her go from the laboratory. Realizing this, Briquet runs, having gone down from the second floor along the bound sheets. She does not reveal to her friends the secrets of her return. Briquet together with her friend Redhaired Martha and her husband Jean (safe cracker) are leaving together to hide from a possible police harassment. Jean is no less interested in this than Briquet.
They find themselves on one of the beaches of the Mediterranean Sea, where they accidentally meet with Arman Lara, the artist, and Arthur Dowell, the son of a professor. Arman Lara cannot forget Angelica Guy, he was "not only a fan of the singer’s talent, but also her friend, her knight." Lara with a sharp look of the artist catches the resemblance of an unfamiliar young woman with a missing singer: her figure "looks like two drops of water on the figure of Angelica Gai." She has the same mole on her shoulder as Angelica, the same gestures, Arman Lara and Arthur Dowell decide to find out the secret. Lara invites the stranger and her friends to take a boat trip and there, left alone with Briquet, makes her tell her story. Without any concealment, she answers the questions first to Lara, then to Arthur Dowell. When Briquet mentions a third head in the laboratory, Arthur realizes who he is talking about. He shows Briquet a photograph of his father, and she confirms his hunch. Friends take Briquet to Paris to find Professor Dowell's head with her help. Arman Lara is in some confusion: he feels sympathy - and maybe something more - for Brika, but cannot understand what attracts him, the body of Angelica or the personality of Briquet herself. Briquet feels that something completely new has come into her life of the singing girl from the bar.
The miracle of “reincarnation” is performed - the pure body of Angelica Guy not only rejuvenates Briquet’s head, it changes the way she thinks. But the small wound that was on Angelica’s foot suddenly makes itself felt: Briquet’s pain starts, her leg becomes red and swollen. Lara and Dowell want to show Brie to the doctors, but she objects to this, fearing that her whole story will be made public. Trusting only Kern, Briquet secretly goes to his laboratory. Meanwhile, Dowell, looking for Marie Laurent, discovers that the girl was imprisoned in a hospital for the mentally ill.
While friends barely release Marie, Kern unsuccessfully tries to save Briquet's leg. In the end, he is forced to again separate Briquet's head from the torso. Kern, realizing that it is impossible to conceal his experiments in the future, shows the public the living head of Briquet (Tom's head is dying by this time). During this demonstration, Marie Laurent, blazing with anger and hatred, denounces Kern as a murderer and a thief who misappropriated other people's labors. To hide the traces of the crime, Kern, with the help of paraffin injections, changes the appearance of Professor Dowell's head. Arthur Dowell, having appeared to the chief of police, asks to search Kern. He himself, along with Marie Laurent and Arman Lara, is present at the same time. They see the last minutes of Professor Dowell's head. The police are going to interrogate Kern. Kern heads to his office, and soon a shot comes from there.
