Piranesi is an extraordinary novel, the setting so well conceived and controlled, the story so luminous, the twists and surprises so unsettling and unexpected, it's quite indescribable. To attempt to describe it would be to give too much away, all I can say is that it's an absolute must-read, and that it will take the reader to places they didn't expect at the beginning. I can't recommend this book highly enough, it's an absorbing, immersive mystery, a triumph of storytelling.