At Wilhelm's doorstep they took leave of each other; Paul went off humming a snatch of Offenbach up the Friedrichstrasse to his home near the Weidendamme.
Wilhelm was tired, but much too excited to sleep.

He lived over again in thought the last few months, and, as often happened lately, he lapsed into painful meditation on his relations to Loulou.

After her departure from Hornberg she had not written to him for eight days.

Then came a letter from Ostend, in which she called Wilhelm "Sie." She said she was very sorry for this, that it would be painful if she called him "Du" and he did not return it, but it would be safer not to do so, as his answer would certainly be read by her mother, and perhaps by her father also, and they would not wish them to say "Du" to each other.
Already this change of tone between them cut Wilhelm to the heart, but almost more still the contents of Loulou's letter.

She spoke a little of the sea, whose breakers continually sounded in her soul, and her thoughts, which accompanied them like an orchestra; she seldom mentioned the delightful time in the mountains of the Black Forest, which remembrance he carried always with him; but a great deal about the Promenade, the concerts, the Casino balls, her own charming bathing and society toilettes, and those of extravagant Parisians, who tried by incredible mixtures of colors and style to outstrip each other.