Documentary about a political episode during the Brazilian military dictatorship, which resulted in the issue of the Institutional Act #5 (AI-5), abolishing freedom of opinion in Brazil, and marking the transition to the toughest period of violation of human rights in the country. The episode was the Congress Assembly on December 12th, 1968, in which its members denied permission to punish congressman Márcio Moreira Alves, as was the Government's wish.