As in the novels "Effi Briest" and "L'Adultera," Theodor Fontane has made a real event of his time the subject of the plot in "Unwiederbringlich." "Unwiederbringlich" is a novel about marriage, indeed a novel about infidelity, in which the almost silent growing estrangement of a couple is described. Tensions rise between Count Holk, a cheerful "man of the moment," and his morally strict wife Christine. Both are relieved by a separation that requires Holk to serve a longer term in Copenhagen. There, Holk falls in love with Ebba von Rosenberg. Behind the subject of the love triangle, Fontane's novel explores the search for understanding, its linguistic possibilities and limitations. "Fine psychology, clear outlines, and highly realistic characters," praised Conrad Ferdinand Meyer of the novel first published in 1891.