I do not know Mario Pratesi's novel but it reminds me of Emile Zola's work,particularly "La Terre " and "Nana".Shot in perfect black and white ,with very beautiful pictures ,it depicts the fall of a young man (Jean-Paul Belmondo,probably dubbed,for I did not recognize his voice) and the peasants' sundown (the last sequence is one of the saddest and one of the most overwhelming in the Italian cinema ).Evil seems to dwell in town even if the prostitute (well portrayed by Claudia Cardinale)is not exactly evil ,she makes love but she cannot feel or give it.Several scenes predates some other works by Bolognini ,notably "la Corruzione" (a seminarian seduced by his father's mistress) or "L'Eredita Bolito" ( the long time lover eager for her partner's dough).A black melodrama.