Un industriel engage un enquêteur pour filer son épouse, espérant secrètement qu'elle le trompe : il pourrait ainsi divorcer et épouser la femme dont il est amoureux.
In Romagna, an Italian district, at the beginning of the twentieth century, the owners of an estate are the professor Edoardo, always lost in reveries, and his wife Maria. They have a son, Robertino, who has a friend: Zvanin. Zvanin is the son of Mingòn and Marianna, two peasants. Dolly is an american cousin and every summer she comes in Romagna. The movie narrates their stories over the years until the post I World War period.