Documentary series that starts in 1977 -with the first democratic elections held in Spain after the Franco dictatorship- and ends 40 years later. The program tells for the first time the history of these years through the voices of its citizens, its authentic protagonists. Each chapter summarizes what happened in one of those 40 years, and includes - in addition to personal testimonies - unpublished archive material, fragments of films and television programs, as well as the music that was heard that year.