Effi Briest by Theodor Fontane

Married off young to a much older man, Effi tries to find happiness in a cold and stifling world of Prussian aristocracy. Years later, a buried secret emerges, unraveling her life and exposing the rigid moral codes around her. The plot is slow-burning and deeply tragic. A powerful critique of society, duty, and personal cost. A quietly devastating novel of innocence lost.