The disaster begins when Berghoff, the first violin of the quartet of the same name, decides to add Schönberg's String Quartet No. 4, op. 37, to the quartet's repertoire. Schönberg's composition strikes him as being the music of a big-city neurotic – like a mirror in which he slowly starts to recognise himself. He gradually loses his self-confidence, and then his wife tells him that she is taking their daughters away, against his will, on a holiday that seems never-ending. One day he finds a valuable violin in his deserted Berlin apartment, put there by some unknown person – a delightful windfall which he plays at the rehearsals of the Schönberg Quartet. The rehearsals become more and more intensive and Berghoff's behaviour increasingly neurotic. He refuses to accept the fact that someone has long since taken the bow out of his hand. A disturbing drama of jealousy runs its course.