Loris is a young man who begins a romance with Francisca, his piano teacher, a forty-year-old who lives dominated by her mother, who was a successful soprano in her youth. Loris goes to live at Francisca's house. They will have as neighbor a sexual obsessive, fan of carnivorous plants and spying on people with binoculars. When they are preparing a trip, Francisca's mother shows up at the house. Her initial indignation soon gives way to a great interest for the young man, which will provoke the terrible jealousy of Francisca.
