The Barcelona Pavilion, the masterpiece with which Mies van der Rohe and Lilly Reich staged their revolutionary ideas in 1929, changed the history of architecture forever. It only existed for eight months but its image was always alive in the minds of generations of architects around the world. The Pavilion is still surrounded by myths and mysteries that this documentary addresses, framing the building in a portrait in two acts of the Barcelona that made possible its construction in 1929 and its reconstruction in 1986. We immerse ourselves in a reflection on the transformative capacity of art, the emotional perception of space and the concept of masterpiece.