I think of Mercy Watson like a superball; there's a bouncy kind of optimism to her stories. She allows me to play, and she makes me laugh. Hopefully readers feel the same way.

I've never worked with a co-author before [Alison McGhee]. Writing for me is a pretty scary thing, so it was a huge comfort to have someone in the room working with me. It became less like work and more like play.

Once upon a time," he said out loud to the darkness. He said these words because they were the best, the most powerful words that he knew and just the saying of them comforted him.

We must ask ourselves these questions as often as we dare. How will the world change if we do not question it?

You are down there alone, the stars seemed to say to him. And we are up here, in our constellations, together.

Miracles and magic pervade the things that I've written, but yet there are no miracles and there is no magic.

I remember wanting to write a book with someone, the someone being Kate [DiCamillo], and we decided to write about two friends. We had no idea how to begin this project - neither of us had ever collaborated with another writer - and I'm pretty sure that we began by giving our two friends a sock, just to see what they'd do with it. And it went from there.