A psychiatrist's experiment in consciousness enables a murderer to steal identities, destroying a family and leaving the scientist psychologically broken.
Story Structure — 5 Plot Phases
The Secret Experiment
A psychiatrist secretly builds a machine capable of probing the human mind. His fascination with Michel Zyto leads him to bring the dangerous patient into the hidden basement laboratory.
Key Events
Mind Machine Conceived — A psychiatrist develops a device intended to probe human consciousness.
Location: The psychiatrist's study
Secret Affair Revealed — Marianne is revealed as the only other person aware of the secret device. Characters: MarianneLocation: The psychiatrist's home
Murderer Interviewed — The psychiatrist interviews Michel Zyto about his sociopathic personality. Characters: Michel ZytoLocation: Mental health hospital
Patient Taken Underground — Michel Zyto is brought from the hospital to the hidden laboratory. Characters: Michel ZytoLocation: Basement laboratory
The Stolen Identity
The experiment causes the psychiatrist and Zyto to exchange minds. Zyto returns the psychiatrist to the hospital and assumes his domestic identity.
Key Events
The Minds Are Swapped — The experiment fails and the psychiatrist's and Zyto's minds exchange bodies. Characters: Michel ZytoLocation: Basement laboratory
Hospital Return — Zyto knocks out the psychiatrist and returns him unconscious to the hospital. Characters: Michel ZytoLocation: Mental health hospital
False Family Identity — Zyto assumes the psychiatrist's domestic identity and enjoys his new role. Characters: Michel ZytoLocation: The psychiatrist's home
Escape From Confinement — The trapped psychiatrist escapes the hospital in an attempt to save his family.
Location: Mental health hospital
The Witness Falls
The trapped psychiatrist escapes and persuades Marianne of the truth. Her warning is rejected, and Zyto murders her to protect his deception.
Key Events
Marianne Believes Him — The escaped psychiatrist convinces Marianne that he is truly himself. Characters: MarianneLocation: Marianne's residence
A Warning Rejected — Marianne warns the wife, but the story is dismissed as absurd. Characters: MarianneLocation: The family home
Witness Silenced — Zyto learns of Marianne's warning and brutally murders her. Characters: Michel Zyto, MarianneLocation: Marianne's residence
Cancer Discovered — Zyto discovers that the psychiatrist's body has cancer. Characters: Michel ZytoLocation: The family home
The Child's Body
After discovering the psychiatrist's cancer, Zyto offers a false bargain and then takes control of the laboratory. He transfers his mind into the child's body.
Key Events
A Dangerous Bargain — Zyto boasts about Marianne's murder and offers to reverse the body exchange. Characters: Michel ZytoLocation: A meeting place
Prisoner In The Basement — Zyto overpowers the psychiatrist and locks him inside the laboratory. Characters: Michel ZytoLocation: Basement laboratory
Child Brought Underground — Zyto brings the young child to the laboratory for another experiment. Characters: Michel ZytoLocation: Basement laboratory
Second Body Exchange — Zyto transfers his mind into the child's body to begin a new life. Characters: Michel ZytoLocation: Basement laboratory
Blood And Ruin
Zyto deceives the mother and attacks her, but the imprisoned psychiatrist escapes. The final struggle restores the minds, destroys the machine, and leaves the survivors devastated.
Key Events
The False Distress Call — In the child's body, Zyto calls the mother and fabricates a dangerous emergency. Characters: Michel ZytoLocation: The family home
Murder In The Bedroom — Zyto lures the mother home and attacks her with a knife. Characters: Michel ZytoLocation: The family bedroom
Bloodied Distraction — The freed psychiatrist confronts Zyto while the dying mother distracts him. Characters: Michel ZytoLocation: The family home's corridor
Machine Destroyed — The minds are restored, Zyto is killed, and the machine is destroyed. Characters: Michel ZytoLocation: Basement laboratory
A Broken Survivor — The psychiatrist becomes a patient and waits for death, hoping the child may recover.
Location: Mental health hospital
Story Breakdown
Forbidden Research — The psychiatrist develops a secret device to investigate the formation of the human mind.
Machine Construction — A hidden laboratory is used to construct the mind-reading device.
Marianne Learns Secret — Marianne becomes the only other person aware of the machine.
The Dangerous Subject — The psychiatrist selects Michel Zyto because of his murderous sociopathic personality.
Hospital Interview — The psychiatrist studies Zyto during an interview at the mental health hospital.
Basement Experiment — Zyto is taken to the secret laboratory for direct testing.
Stolen Identity — A failed experiment exchanges the minds of the psychiatrist and Zyto.
Mind Exchange — The machine causes both men to occupy the wrong bodies.
False Family Role — Zyto returns to the family home and impersonates the psychiatrist.
Marianne's Warning — The escaped psychiatrist seeks Marianne's help while Zyto protects his deception.
Truth Revealed — The psychiatrist convinces Marianne that the body exchange occurred.
Witness Murdered — Zyto kills Marianne after learning that she tried to expose him.
The Child's Body — Zyto abandons the stolen adult identity and pursues a new existence through the child.
Cancer Discovery — Zyto learns that the psychiatrist's body has cancer.
Second Transfer — Zyto uses the machine to place his mind in the child's body.
Family Slaughter — Zyto uses deception and violence to remove the remaining obstacles to his escape.
False Distress Call — Zyto fabricates an emergency to lure the mother home.
Bedroom Attack — The mother is attacked with a knife after returning home.
Final Reckoning — The psychiatrist escapes, confronts Zyto, and ends the experiment at terrible cost.
Corridor Confrontation — The dying mother distracts Zyto and allows the psychiatrist to overpower him.
Broken Aftermath — The minds are restored, Zyto is killed, and the psychiatrist becomes a hospital patient.
This deftly made French psychological thriller terrifies with its exploration of an experiment gone horribly wrong. Dr. Marc Lacroix, a psychiatrist specializing in brain functions, is obsessed with the link between mind and spirit. To find his link he studies the criminally insane. He builds a secret machine, known only to his mistress Marianne, in which he hopes to exchange minds between humans. He simultaneously wants to help the mentally ill recover, and he wants to experience their madness. He chooses the psychotic killer, Zyto, a man who stabbed at least three women, for his experiment. The initial experiment is successful and the two exchange minds. But trouble ensues when Zyto refuses to reverse the switch. There is little Marc can do when Zyto takes over Marc's life, and more ominously his wife and child whom are unknowingly in mortal danger. Marc, encased in Zyto's body, is returned to the asylum. Will Marc's wife recognize the danger? Will Zyto kill again?
