Raven Summer by David Almond

Liam and his friend Max find an abandoned baby in a meadow. Liam's writer father and artist mother end up making friends with the baby's foster family and eventually his mother decides to adopt her. Liam makes friends with two of the other foster children, Crystal and Oliver. When Liam finds out Oliver's true story, he must evaluate what he thinks about friendships and life in general.

This was an extremely quick read; however the subject matter is extremely heavy and thought provoking, so I recommend reading this when you have the time to devote to it. Although this is a very heavy read, it is written beautifully and in such a way that the heaviness of the subject matter doesn't detract from the beauty of the writing itself (if that makes any sense). Basically it is written well enough that I didn't feel boggged down by all of the depressing (if you think about it) subject matter.