In the figure of Ettore Zambrini, a small industrialist with a dream of opening a factory overlooking the Autostrada del Sole, Montaldo offers us an effective narrative transposition of the 'animal spirits' that governed the economic boom in Italy at the time. He is a character of contradictory humanity: capable of handling business, overdue bills, trade union relations, marital betrayal, but also the passion that binds him to his wife with equal unscrupulousness.

During the winter of 1944, the partisans stationed in the Ligurian Apennines must go to a factory in Genoa, in order to pick up a delivery of weapons. Meanwhile, there's a strike in the city and the Nazis are trying to suppress it violently. The factory becomes the scene of fighting between the Germans and the partisans but the latter, aided by the workers, will be able to get the better.