This is a fabulous, surprisingly sweet take on dystopian sci-fi. Giant monsters roam the land, society has broken down into small villages, and teenaged Rainbow is searching everywhere she can for her semi-feral younger adopted sister, Jonna. Rainbow is relentless and optimistic, and Jonna herself is an amazing spitfire who can fell a monster with a single punch. It's really compelling stuff, and it seems suitable for fairly young ages, assuming they can handle the darker world-building (the sisters are looking for their father, and many people have lost entire families and towns). I can't wait to read more of these girls' adventures!