Story of impossible love between a knight and his sister. From them born a son who is repudiated by the gentleman, who takes him to live with monks in a monastery. When the boy grows up, escapes from the monastery to see the world and especially the sea. On the way he meets a peddler who teaches him to function in life.

As he does at the end of every summer, Antonio climbs onto his roof to sweep out his chimney. From this vantage point, he sees that repairs have begun on one of the neighbouring houses - the one formerly inhabited by the "Nazi" (a guy's name), which after ten years of abandonment is known to the whole neighbourhood as the "mystery house". With the arrival of fall, Antonio will uncover love, deception, and death, by watching through his window.