~4.5 
 If you happen to be a fan of Arsene Lupin, Sherlock Holmes, and hard scifi, then you absolutely need to read this book. 
 If you're not familiar with Lupin, he's the quintessential Gentleman Burglar, an insouciant Frenchman whose talent for disguise and deception is matched only by his enjoyment of criminal capers. One of my favourite Arsene Lupin tales, "Sherlock Holmes Arrives Too Late," has the intensely earnest Great Detective track down his rival, only to have Lupin steal his watch. (Doyle was not amused. After threats of legal action, the detective's name was changed to Herlock Sholmes.) 
 The Quantum Thief opens with le Flambeur trapped in a Prison in which he must endlessly play game theory paradigms such as Prisoner's Dilemma against his fellow cellmates. Every day, he defects, dies, and finds himself back in his cell. But when a mysterious woman named Mieli offers an opportunity for rescue, le Flambeur is less than convinced. For one thing, what if it's just another more intricate game of the Prison? For another, what does she want so badly that she's willing to trust the thief? Le Flambeur soon discovers she won't take no for an answer, and that his first task is to steal back his own memory from a world where time is currency and privacy is paramount. 
 If you can imagine Arsene Lupin in a complex science fiction world inhabited by people enhanced by various forms of abstruse technology, then you're getting close to picturing Jean le Flambeur. The references to Lupin are overt--in fact, Flambeur named himself after his literary hero. Rajaniemi also captured Lupin's rather delightful sense of humor. A few of my favourite quotes from le Flambeur:"Raymonde, meet Mieli. Mieli, meet Raymonde. Raymonde and I used to be an item; Mieli, on the other hand, treats me like an item.""And you forget something. They know me. That makes them bad guys by definition." I loved the whimsical way in which Rajaniemi played with the classic stories--Le Flambeur is even pitted against a brilliantly analytical Boy Detective. 
 At the same time, the book itself is far from a simple parody. The true enchantment of the story comes from the complex world that Rajaniemi creates. At first, I was utterly bewildered by the mention of exomemories and oubliettes and tzaddiks and copyclans and pellegrinis and sobornosts, but as I ventured farther into the story, the gloriously complex, methodically considered, utterly creative world began to come into focus, and I was utterly enchanted. The story is an exploration of the way that privacy, memory, and even the sense of self can be shaped by technology, but it's also just a downright entertaining caper. As le Flambeur puts it,"Fighting a cabal of planetary mind-controlling masterminds with a group of masked vigilantes--that's what life should be all about."