Mortal Engines by Phillip Reeve
In a post-apocalytpic world, cities are flying around a little above the ground. The biggest cities (like London) conquer the smaller ones. There are also pirates that capture cities for their own purposes. In this universe, there are people trying to find other people and complete their goals.
Fever Crumb is set in a futuristic post-apocalyptic London. Population is now less than 100,000. A group of people that view themselves as homo-superiorous had ruled the city. However, due in part to lack of reproduction, they had been killed off by the local population. The book focuses on a group of "engineers" that work to support science regardless of who is in power. They stress rationale thought above all else, and try to avoid personal superstition and human relations. One day, however, a little girl appears on their doorstep. She is somewhat "different" with miscolored eyes. Dr. Crumb takes her in and raises her as a fully rational engineer. At 14, she is sent out to help with an archaeological site. In the process, she runs into some people that think she is one of the previous rulers. An old hunter and boy try to hunt her down, providing the drama. Eventually, new rulers come into London, with plans for moving cities. They discover Fever's parentage and Fever decides she wants to be out on her own.
