美丽的威尼斯，一对情侣死在河边，男死者被人捅死，女死者是溺死，警察很奇怪，为什么凶手溺死女死者之后还把她从河里捞出放在岸边。为了把凶手捉拿归案，警察们对这对情侣的社会关系进行调查，发现有位女士跟他们过从甚密，随着进一步调查，警方发现男死者不但是个瘾君子，还是性变态，案件调查进行到一半的时候，一名妓女被杀，凶器是一把剪刀，紧接着，那名跟两位死者关系异常的女士也被杀了，一名变态大学生浮出水面，大学生承认了自己的罪行，可是案件似乎还不是表面上那么简单。Inspector Angelo De Pol (Jeff Blynn) is assigned to the case of a double murder in Venice, the victims were a married couple. He suspects that a psycho killer in on the loose, however during the investigation the inspector discovers that the husband was a sex maniac and a drug addict. Soon afterwards bloody killings begin to occur.