Xavier Vilato, Kahnweiler's great-nephew, recounts during a visit to the Museo de Barcelona, the happy and creative atmosphere of the "Boulogne Sundays" organized by Kahnweiler, which lasted from the end of the First World War to the death by Juan Gray. He evokes his memories of his youth, Kahnweiler's erudition, the artists who came, painters, sculptors and writers, and of course, his role as a dealer with Picasso.