Super Short Summary

Piranesi by Susanna Clarke is an epistolary fantasy novel narrated through first-person journal entries by Matthew Rose Sorensen, also known as Piranesi, who is trapped in a labyrinthine House with grand halls and seas, only remembering this world. He aids another inhabitant, the Other, who seeks arcane knowledge, leading to a journey of self-discovery, identity fragmentation, and eventual partial re-integration into modern society.