La machine (1994)
Psychiatrist Marc Laxroix is a scientist who studies the brains of criminals. He has a unhappy and loveless marriage with Marie Lacroix and they have a son named Léonard. Marc also has a mistress named Marianne, who doubles as his confidant. In secret, Marc has built a machine to transfer one person's mind to another's in his old house, but has yet to test it. Only Marianne knows of its existence. When the serial killer Michel Zyto is sentenced to life in the institution where Marc works, Marc decides to study his mind and brings him to use the machine, leading to a mind exchange. When Marc asks Zyto to press a button to restore their minds, Zyto refuses and traps Marc in his body, using Marc's body to lock him up in the institution. He then goes to Marc's house to be with his family. Will Marc be able to regain control of his body?