The thing that I love best about Young Reader and Middle Grade books is that they often are able to speak towards valuable morality in a way that adult fiction doesn't. I don't mean "stories with Morals" I mean stories that make us as readers evaluate what morality is. Middle Grade readers are just learning to find out what their own morality is. What grate YR/MG books do is give their readers the opportunity to think complexly about people and events. With Pax, there's a very strong anti-war message. It's not the kind that bashes you over the head, but is the kind that makes the reader consider the cost of war in a way that is real. It also focuses the cost beyond just a human perspective and causes the reader to consider human war's impact on the environment. Pennypacker isn't trying to tell a story than ends with "and the moral is" but rather trying to turn young reader's thoughts towards the impact of violence in their every day lives and in the lives of those facing war. She does this beautifully and in a way that young readers will be sure to enjoy. I will say that it gets pretty teary-eyed and parts and there's some content appropriate violence but overall I think this could be really good for 1o-12 year old readers, maybe even lower if they have already read and understood books like Charlotte's Webb.