"Piranesi" is a novel by Susanna Clarke that follows the story of a man living in a mysterious, labyrinthine world filled with grand, decaying architecture. The protagonist, known as Piranesi, explores vast halls and endless statues, documenting his findings in journals. He believes he is the only inhabitant of this strange place, which he calls the House. As the story unfolds, Piranesi encounters another character, referred to as the Other, who introduces complexities and questions about reality and identity. The novel blends elements of fantasy and philosophical inquiry, inviting readers to ponder the nature of existence and the power of memory.