This series examines through images events of the twentieth century that have marked our memory and our imagination, revealing the secrets of audiovisual archives. The collection aims to uncover and rediscover known or unpublished images that bear witness to our history. The audiovisual document becomes a piece of evidence that it is up to us to question, to make people talk. The image is scrutinized, dissected, and often, Mysteries in the Archives takes our gaze away from what the camera operator had seen or expected. Each episode is constructed as an investigation. Some are about cheerful and amusing topics, others are about more solemn, momentous events.