DS4 (5 in Feb) is reading easy chapter books. His reading level is probably high end of 3rd grade, maybe higher, but he loses interest in complex plots, things with a lot of blah blah blah, and themes above his age level. At this stage in her reading development, DD snarfed up those Rainbow Fairy books, but he's not interested. Suggestions other than Magic Treehouse (he's slightly mixed on those) and Magic Schoolbus chapters (he loves these, but he's read most of the ones at our library)? He recently has been reading the Ivy and Bean series as well, if that helps.