I've had Greenglass House on my stack for a while. I finally got to it and finished it up a few days ago. It was a great book and I am so glad I made time to read this one.
I'm not a big mystery fan and I don't seem to find that many great mysteries for kids. But this was a mystery I loved and I think kids will love it too.
The story is about a boy named Milo who lives in an inn that his parents run. Many of the guests at the inn are smugglers but Christmas vacation is usually quiet, with no guests. This holiday is different however, as several guests appear at the inn. It becomes clear to Milo early on that there is something suspicious going on so he and his friend Meddy, try to solve the mystery.
This mystery is full of all things kids love in a mystery-an old house, great characters (they reminded me of characters in a game of Clue), lost things, treasure hunts, maps and bad guys.
I'm thinking this book is perfect for grades 5-6ish. It is not short (about 400 pages) but I think if i were teaching 5th, I would definitely consider it for a read aloud. This is also one that kids would enjoy reading independently.