This article focusses on the novel Czyściec (Purgatory,1921) by assimilationist writer Aniela Kallas (alias for Aniela Korngut, 1868–1942). Written in the form of woman’s diary from the period of the Great War, the novel diagnoses the war as a turning point in European and Polish history, and acknowledges the new character of the war manifested both in frontline fighting and in the civilians’ circumstances. The work represents the war experience and likewise points to a crisis in the assimilationist movement, that is, marginalization of the Jewish perspective and the turn toward radical Polonization.