Elephant and Piggie have a very large input. They have a distinct aesthetic taste. They like books that are philosophical. They like books that are dialogue-driven. They like books that are about issues that they live with, in their own elephantine and porcine ways.

A book, being a physical object, engenders a certain respect that zipping electrons cannot. Because you cannot turn a book off, because you have to hold it in your hands, because a book sits there, waiting for you, whether you think you want it or not, because of all these things, a book is a friend. It’s not just the content, but the physical being of a book that is there for you always and unconditionally.

The common thread of the series is that these are the books that Elephant and Piggie like to read. Elephant and Piggie are retired, so this is what they do in their spare time. What will they end up wanting to read? Time will tell. We've got to let that evolution happen as the series goes on. Any return of a character would have to be organic, would have to be, for example, Laurie Keller saying, hey, I really want to do this, and me feeling that there's a story there, rather than just saying, yeah, we can get three books out of these characters.

Writing for children is as easy as describing the history of the Byzantium in three words.

If you ever find yourself in the wrong story, leave.

When you make a decision, you don't have to be locked into it. One of the ways that you grow is by starting over. There are all kinds of really powerful things in that moment, which is what makes story work. Part of Laurie's Keller personality is this ability to revise, to come back and to look at things from a different angle. I don't want to tell stories too much out of school, but Laurie Keller is the only person who sent me a card on my birthday and then sent me a revision.

I've been lucky enough to have made enough of these types of children's books that while I don't necessarily know what works, I know what doesn't work. I've got a sense of the rhythm and the form. With this series, I get to play with ideas that I would never have myself.