I really liked Jean-Louis Trudel's La Lune des jardins sans soleil ("The Moon of Sunless Gardens "). It's a very original, creative science-fiction novel set in Earth's future when much of the population lives in vast underground colonies. Because each colony has strict population limits, unauthorized children are sent to live in orphanages where they have only a life of drudgery to look forward to (and many turn to drugs or even prostitution). One of the orphans, Corinne, decides to take a chance and stowaway aboard a military starship full of "bonsai-children", genetically-modified warriors bred to fight a war that ended long ago. The bonsai-children adopt Corinne as their own and decide to try to rescue the rest of the orphans left behind.