Based on extensive research, the author describes and outlines the role of the Portuguese Communist Party in the revolution of April 1974 and in the moments that suceeded it. Combining scientific evidence - the book is based on the author's thesis, coordinated by historian António Costa Pinto and political scientist Carlos Taibo, a professor at the Autonomous University of Madrid and a columnist for El País and Cadena Ser radio, among others - with a text for the general public, the author offers a document of enormous importance for understanding one of the most discussed moments in Portugal's recent history.