Galip is a lawyer living in Istanbul. One day, his wife Ruya suddenly disappears. Did she leave him to return to her ex-husband, or perhaps for the sake of her half-brother Jelal, a well-known journalist who has also vanished?

As Galip tries to make sense of the situation, he finds himself gradually adopting Jelal's identity: wearing his clothes, answering the phone calls he receives, and even writing his articles for the newspaper. Galip searches for clues as he wanders through the atmospheric city, where every corner is a sign of its history, but the nature of the mystery keeps changing – until he receives threats to his life, and then he begins to fear the worst.

In the enchanting setting of Istanbul, aside from searching for Ruya and Jelal, Galip ultimately seeks the true identity of his city, but more importantly, he searches for himself.

"Because The Black Book starts from my childhood where I spent the majority of my life and tells the adventures of a hero of my age, it is natural that I have often been asked: 'How much Galip are you?'. Perhaps the details of my life – the shopping, the glances I threw from my window at Aladdin's shop across the street, my conversations with Mrs. Kamer, who was a real person, my lonely Saturday nights, my walks through the empty streets of the city at night – might resemble Galip's.

But Galip's deep loneliness, the melancholy that invaded him like a disease, the sad darkness of his life, are fortunately not my own deep wounds. I envy Galip for his patience, his seriousness, the strength with which he carries his pain; I admire him also because, despite everything that has happened to him, he silently approves of life. I became a writer because I did not possess his strength for all of this." From the afterword of O.P.