While in Paris, Rorimer had an auspicious encounter with Rose Valland, an art historian and employee of the Galerie Nationale du Jeu de Paume. During the German occupation of France, the Reichsleiter Rosenberg Taskforce—the Nazi organization in charge of the systematic looting of art and cultural artifacts—designated the Jeu de Paume museum as the central location for storing and sorting their stolen treasures. Valland was the only member of the museum's original staff retained by the Nazis. She spied on the Nazis, who did not realize that she spoke German, and kept detailed records on the transportation of artwork stolen by members of the Third Reich. She passed information on to the French Resistance and to Rorimer.