Jonathan Strange and Mr. Norrell, Susanna Clarke’s bestselling novel, left me cold, but sixteen years later, the much slimmer “Piranesi” is an accomplished, moody take on a science-fiction trope of the hidden other world. In the grand universe of the House, with its countless massive halls amidst clouds, its flooding waves, its innumerable ornate statues, a meticulous madman named Piranesi lives, roams, and scientifically records in notebooks. The only other occupant is the Other, a friend … or is he? When an intruder arrives, Piranesi’s world comes under threat. Clarke has constructed a complex puzzle requiring the reader to solve the mystery of where, who, and why, and she does with extraordinary finesse. Written in a gothic style, the novel wrapped me in the grip of a memorable hero and an almighty, intricate brain twister. And an enduring character is the House itself, evoked in atmospheric prose. The ending is wonderful and wonderfully revealed. I’m reminded of some classic I might have read half a century ago, perhaps a half-remembered Wilkie Collins novel. Unusual, eerie, and compelling, Piranesi is a fine, intelligent read that sticks in the memory.