Irena "the unknown" (Rappoport) is an Ukranian young woman living in the Italian city of Velarchi. Soon we discover she has an horrible past of violence and humiliations. To pursue a mysterious aim she manages, by any means, legal and illegal, to get the job as an house servant for a wealthy couple with a little girl. She grows closer and closer to the family, especially to the girl, who suffers from a rare neurological disease. But someone will come back from her past, bringing new horrors and violence .