To mark the opening of the new Fondation Cartier, designed by Jean Nouvel, a temporary pavilion is installed on the Place du Palais Royal. Conceived as both a mediation device and an architectural gesture, it accompanies the discovery of the new building. On the one hand, the structure introduces the project by retracing its history through a micro-exhibition combining images and texts, revealing successive historical layers of the site. On the other hand, it draws upon the founding principles of Jean Nouvel’s architecture, transparency, movement, and stratification, to define its own structure and envelope. The installation thus operates as a transitional object, both narrative and conceptual, echoing the identity of the building it announces.