A German ornithologist casually discovers some old tapes on which a psychologist has recorded the mysterious doings happened into those isolated walls. So he learns about a gloomy story of incestuous loves and trivial betrayals that will lead to a bloodbath orchestrated by an unexpected crazy character.
An old professor rents a mysterious old villa, and finds a tape recorded by a previous occupant, detailing her debauched lifestyle and the events leading to her murder.