It is a dramatized version of the 1969 kidnapping of the United States Ambassador to Brazil, Charles Burke Elbrick, by members of Revolutionary Movement 8th October (MR-8) and Ação Libertadora Nacional (ALN).

[3] In 1969, as a member of Revolutionary Movement 8th October (MR-8), a student guerrilla group, he participated in the abduction of the United States ambassador to Brazil, negotiating to gain release of leftist political prisoners.

Gabeira (played by Pedro Cardoso and named Paulo in the film) as a student joins the radical movement after Brazil's military overthrew its government in a 1964 coup.

In 1969, he and his comrades decide to kidnap the American ambassador to protest the Brazilians' coup; the film busies itself with the group's conspiring and execution of the crime.

The main characters include: The film had mixed reviews, in part because of its fictionalizing Brazilian history, and its uneasy portrayal of terrorist activities by student radicals.

[5] Stephen Holden of The New York Times wrote, "Four Days in September is an uneasy hybrid of political thriller and high-minded meditation on terrorism, its psychology and its consequences.