Portrait of Henri Langlois, founder of the Cinémathèque Française and the Musée du Cinéma, whose life coincided with forty years of the Cinémathèque, from 1936 to 1976, years of efforts to safeguard and publicize the world's film heritage, and to encourage the arrival of many filmmakers. Beyond the hyper-realistic portrait of a man, this portrait is also a history of cinema, and an initiation to the seventh art for the younger generations. This documentary was conceived as a fiction film because it works with sequences that follow one another, with twists and turns, moments of humour, feelings of injustice, but above all because Langlois appears in it as a character, like the hero of an adventure. The story of Henri Langlois is an epic, that of a destiny.