Antonio and Teresa are a couple who live in a flat in San Sebastian. Ursula Michelena, an elderly woman over 70 years old, lives on the top floor. Ursula is secretly in love with Antonio, whom he continually spies from one of the windows of her house. One night she sees Antonio and Teresa making love and that fact excites her violently, in such a way that she asks Antonio for a secret appointment and tells her that she is pregnant and that the son she is waiting for is his. Úrsula, according to her version, has become pregnant looking at Antonio and Teresa making love.