The plot is freely adapted from the 1988 book The Prisoner by the former brigadeist Anna Laura Braghetti, which tells of the 1978 kidnapping, detention and murder of Aldo Moro by the Brigate rosse.

A small group of terrorists of the Brigate rosse rent an apartment. They kidnap Aldo Moro, former prime minister of Italy and leader of the Democrazia Cristiana party. Moro writes many letters to politicians, Pope Paul VI, and his family, but the Italian government refuses to negotiate. A female member of the group, played by Maya Sansa, suffers doubts about the plan.

Peppino Impastato was a son of a family in collaboration with the Mafia. Peppino rebelled against his father, rejected this heritage and started a radio station denouncing the Mafia. On the same day Aldo Moro's body was discovered in the back of a car in a Roman street in May 1978, Peppino was murdered, first stabbed then explosives strapped to his body, tied to a train track where his body was blown up. This film is his story.