This documentary inquires and questions us on being citizens after the Shoah, on events that could be repeated: would we be mere spectators? The film takes place entirely at Milan Central Station, from whose platform 21, between late 1943 and early 1945, where 15 trains loaded with deported Jews. The facts and the facts of history are told with a fast-paced, full of stories of Italian Shoah emerge from the memories of eyewitnesses and their children and grandchildren. The movie is about young people in particular, that even adults seem to be within light years from those events. For this reason it was chosen to take as much current languages, such as 3D reconstructions and computer graphics. Only rigorous knowledge of the facts, as well as the thrill of listening to witnesses, make it possible to allay concerns expressed by Primo Levi which, unfortunately, you see the signs at every level of our society. For educational use of the film was producing a guide for teachers, with a series of short but important insights and much food for work to be done in class.