There's a secret tree fort and you're not invited! In this hilarious and hugely imaginative sibling story from the creator of the internationally celebrated Ike's Incredible Ink, two sisters are told to go and play outside on a beautiful day. The little sister wants them to play together but the big sister, instead, wants to sit under a tree with a book. So the younger sister decides to tempt her with a description of her super-cool, super-secret tree fort. Just what will it take to get her sister to look up? The promise of a water-balloon launcher in case of attack? A trapdoor to look at the stars? A crow's nest where they can see how many whales pass by or watch for pirates? Or the very best part of all, which can't be revealed, because it's a secret?