When Romania at last entered the war on the Allied side in 1916, Marthe worked at a hospital in Bucharest until the German army burned down her home in Posada, in the Transylvanian Alps. She fled the country to join her mother and daughter in Geneva after a quarantine exile, imposed by the German occupiers, in Austria-Hungary (as a guest of the princely family of Thurn und Taxis at Latchen). There she continued to write. For most of her life, she wrote every morning until lunchtime—her journals alone fill 65 volumes.