Oliviero is a burned-out writer, living at his estate near Venice, his dead mother dominating his imagination. He is also a degenerate: sleeps with his maid and his ex-student, hosts Bacchanalia for local hippies, and humiliates his wife Irina in front of strangers. She lives in terror. When a young woman is murdered, police suspect Oliviero. Things get complicated when his young, beautiful, and self-confident niece, Floriana, pays an unexpected visit. A silver-haired stranger observes. More women die, and thoughts of harming Irina give Oliviero new inspiration. What's Floriana's game and who's the observant stranger? Watching all is a black cat named Satan. 　　译文(2): 奥利维耶罗是个精疲力尽的作家，住在威尼斯附近的庄园里，他死去的母亲支配着他的想象力。他也是一个堕落的人: 和他的女仆和以前的学生上床，为当地的嬉皮士举办酒神节，在陌生人面前羞辱他的妻子 Irina。她活在恐惧中。当一名年轻女子被谋杀，警方怀疑奥利维耶罗。当他年轻、漂亮、自信的侄女 Floriana 突然造访时，事情变得复杂起来。一个银发陌生人观察着。更多的妇女死亡，伤害伊丽娜的想法给奥利维耶罗新的灵感。Floriana 在玩什么把戏，谁是那个善于观察的陌生人？一只名叫撒旦的黑猫注视着一切。