[1][2] It is an independent documentary about the Piazza Fontana massacre and the death of anarchist Giuseppe Pinelli.

Among those interviewed are workers and militants from the Lotta Continua movement, which Pinelli was a member of, as well as deputy Achille Stuani, member of the Italian Communist Party; Licia Pinelli, Giuseppe's widow, and several lawyers including those who defended Pietro Valpreda, who was arrested for the bombing.

The film was made by Pier Paolo Pasolini on the proposal and with the collaboration of some militants of Lotta Continua, a formation of the communist-oriented far-left.

[5] Pasolini wanted to make a denunciation film which would focus on the anthropological and social aspect of the country during that period.

The global and almost intolerant criticism that these express against the Italian state and capitalist society finds me in complete agreement in substance, even if not often in form.

[9] In order to avoid any potential problems with the law, Pasolini and Grimaldi decided to leave their names out of the film's credits.