交换：你兄弟

　　生物学教授詹尼西尔（Pierre Brasseur 饰）因一次车祸使心爱的女儿克莉丝汀（Edith Scob 饰）面容尽毁，女儿伤愈后只能终日戴着瘆人的白色面具，痛苦非常。爱女心切且心怀内疚的詹尼西尔与助手路易丝（Alida Valli 阿莉达•瓦莉 饰）伪装克莉丝汀失踪、死亡的假象，暗中诱拐与女儿年龄相仿的女性，将其麻醉后剥掉面皮，移植到克莉丝汀脸上。　　但手术接连失败，牺牲者也不断增加。亲眼所见诸多同龄女孩惨遭杀害，克莉丝汀心中痛苦不已。另一方面，众多女孩失踪的案件也引起了警方的注意，他们逐渐将目标锁在疯狂的詹尼西尔身上……

　　一起连环凶杀案吸引了警长索恩（大卫·莫瑞瑟 David Morrissey 饰）的注意，这位穷凶极恶的凶手手中已经有了三条人命，然而，第四名受害者却侥幸逃过一死。警方和民众都认为这是凶手的百密一疏造就的结果。然而，可怕的是，没过多久，索恩就发现，犯错的不是凶手，而恰恰是自己，因为尽管保住了一命，但这位幸存者却无法提供任何情报。　　几起在同一时间、使用同一手法在两个不同地点作案的谋杀案让警长索恩十分警觉，随着时间的推移，迷雾渐渐拨开，他发现，自己所要面对的并非仅仅一名嗜血残暴的杀人魔王，而是两个在暗地里相互勾结、相互鼓励的反社会分子。

　　The main character is Dr. Max Holst, a successful neurosurgeon. One day an intense little man named Steinmetz shows up, who has the real ability to create objects out of thin air, using only his mind. As no one believes him at first, he is held at a ward for mental patients, but manifests the key to his door and escapes. As he has a special interest in Dr. Holst, Steinmetz subsequently invites Holst to his large mansion, which is full of expensive paintings and sculptures, and proves to him that he can in fact materialise objects. Steinmetz’s abilities are evolving by leaps and bounds, and is progressing from being able to create objects only to being able to create living things. His ultimate ambition is to be able to create a human being. He tells Dr. Holst that if he will only perform a certain brain operation on him, Steinmetz will become able to attain his goal. He’s got all the necessary equipment set up in his basement. Dr. Holst, however, is too spooked by the whole thing to agree to this mad scheme, and refuses. Steinmetz then sets about manipulating Holst’s life, to pressure him into performing the operation. By then Steinmetz has become able to create a temporary human being, and in the hope that he can perhaps make his own creation perform the operation, he manifests a doppelganger of Dr. Holst. This double proceeds to take over Dr. Holst’s life, creating chaos for him professionally and personally. And then Dr. Holst starts fighting back. The ending has the dual virtue of being both unexpected and satisfying.

 一位无家可归的失忆男子接受一场实验性医学手术，术后醒来发现自己获得新的能力，可以看穿人们内心最深处的伤痛，真实和幻象之间的界线也因而模糊难辨。