For the man we know as Piranesi, the House with a capital letter is the whole World. "Since the beginning of the World, fifteen people have definitely existed in it," and Piranesi is the fifteenth. He explores the endless Halls decorated with majestic Statues and schedules the Tides sweeping the lower floors. Clouds swim to the upper floors and birds fly in, and on Tuesdays and Fridays Piranesi meets the Other. "The House's beauty is unspeakable," Piranesi writes in his diary. "His kindness is unlimited." But one day he discovers traces of man number sixteen...