Four Days in September (Portuguese: O Que É Isso, Companheiro?) is a 1997 Brazilian thriller film directed by Bruno Barreto and produced by his parents Lucy and Luiz Carlos Barreto. It is a fictional 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).It was nominated as Best Foreign Language Film at the 1998 Academy Awards.