Immacolata, a country girl, falls in love with Count Claudio, but he, tired of her advances, denounces her to the authorities. She is declared insane and shut in an asylum.

Lady Mercedes, anxious to rehabilitate the girl, lakes her home to her parents for a "holiday". However, her relatives reject her and "rent" her out as a "mare" to a neighbour.

She runs away to hide in the woods, where she falls in love with Osiride, the Poacher, but they are soon caught. Returned to her family, she escapes again, and her even more fantastic adventures begin. She meets a travelling salesman and three gypsies, and they poach together on Count Claudio's estate. They are caught, and the girls are hired out to a factory. Here, Immacolata incites the workers to occupy the building, and she is arrested once more and taken to the asylum. Osiride, disguised as a bear, tries to rescue her, but is killed. Crazier than ever after these experiences, Immacolata is shut away in the asylum, and the "holiday" is finished for ever.

Probing the problems of sanity, equality of the law for all and social prejudices against the insane, Tinto Brass uses the language of paradox, humour and fable, to touch the emotions, rather than the intellect of the viewers.