I would like the name of a story I read, maybe a year ago, about an underground colony of people that were waiting for the return of a astronaut. The colony had a clan type setup with the more powerful clans being closer to the ground level above. It was a very violent colony, resources were running out because of overcrowding. It was a longer story, I think. It was, also, the start of a series, I believe. One of the next stories involved a clan leaving the colony and working for the military trying to fight a alien species. Thanks for any info.