A man walks down the exterior staircase of some building. He passes a small window and sees a young woman standing at a washbasin, drying her hair with a towel that covers her face. Fearing to be seen, the man starts down the stairs, only to return to the window afterwards. He again looks in the same window and this time he sees a man brushing his teeth who gives him an unsettling smile. In his autobiography, Roman Polanski says that the theme was set for him by a supervisor at film school.