Apollo in The Moon House (PB) (2006)

Apollo Jones, a ten year old boy growing up in Newark, New Jersey, is nicknamed the Moonboy by everyone. He has no friends except a homeless man named Raggedy Jack. One day Jack tells him a story about a special garden behind the Moon, a place very few people have seen. Blocks of silvery light show him the way to another world, where he must face a terrifying beast in order to rescue a princess. In the end Apollo realizes that being a Moonboy isn't so bad...