In Ghosts, the second part of Paul Auster's The New York Trilogy, a private eye called Blue is hired by a certain White to shadow a man called Black. Black lives in a small apartment in Brooklyn; Blue moves into an equally small apartment just across the street from Black. He is alarmed to discover that Black spends most of his time at his desk by the window, writing in a notebook with a red fountain-pen. In the evenings Black reads, and through his binoculars Blue can just make out the title of Black's book: Walden, by Henry David Thoreau.

Accordingly Blue obtains his own copy of Walden – a 1942 edition published, by coincidence, by one Walter J. Black – thinking it might help him solve the mystery of his assignment. But, like almost every reader of Walden, from Emerson to Stanley Cavell to Auster himself, Blue finds reading this book is “not a simple business”:

Whole chapters go by, and when he comes to the end of them he realizes that he has not retained a thing. Why would anyone want to go off and live alone in the woods? What's all this about planting beans and not drinking coffee or eating meat? Why all these interminable descriptions of birds? Blue thought that he was going to get a story, or at least something like a story, but this is no more than blather, an endless harangue about nothing at all.

The next day Blue tries the book again, and finally comes across a sentence he can understand: “Books must be read as deliberately and reservedly as they were written.” Blue realizes that “the trick is to go slowly, more slowly than he has ever gone with the words before.” Nevertheless, he still finds the whole business excruciatingly painful, and curses Black for torturing him in this way. “What he does not know,” the anonymous narrator remarks, “is that were he to find the patience to read the book in the spirit in which it asks to be read, his entire life would begin to change, and little by little he would come to a full understanding of his situation – that is to say, of Black, of White, of the case, of everything that concerns him.” Instead, Blue throws the book aside in disgust and goes out for a walk, not realizing “that this is the beginning of the end.”