The Windup Girl by Paolo Bacigalupi
Imagine a post-petroleum world where internal combustion and electricity are vanishingly rare and almost all energy comes from biology: muscles and, ultimately, food. Can't? Let Paolo Bacigalupi do it for you. In this future, the entire global economy is built on calories: growing them as crops, consuming them as food, expending them as energy. Everything from guns to cars to factories runs on springs, wound by hand by humans or monstrous genetically altered elephants. As digital technology faded, biotech mutated out of control, and as a result humanity is ravaged by genetically engineered plagues and the streets are infested with genetically modified supercats. Bacigalupi is a worthy successor to William Gibson: this is cyberpunk without computers. Our heroine is Emiko, the windup girl of the title. She is a "New Person," a heavily genetically modified girl brewed up from scratch by the Japanese as a toy. But her DNA is not so compromised that she doesn't still yearn to be human.