A Milanese company buys a plot of land in Naples for the construction of an industrial plant. In this part of the city's outskirts in the post-war period, many poor families live in terrible conditions. Nevertheless, they are forced to leave. Some of the elders rebel and end up dying as the makeshift homes collapse.
The others rebel against the Milanese civil engineer in charge of the project. The engineer escapes and takes shelter in the house of Annina, a girl who lives in the same area where the accident happened. Salvatore, the most cunning of the rebels, has a group of friends pose as relatives of the dead people and together they all go to Milan to seek damages. The industrialists, however, do not want to lose money and offer them jobs in the factory, which the Neapolitans willingly accept. Later however, the company faces failure, and is saved when the Neapolitans succeed in getting help from their fellow emigrant citizens elsewhere.