We All Speak Z - children's book

"We All Speak Z" by Melanie Hertling.  Illustrated by Heiner Hertling.  Hard cover. 

We All Speak Z tells the story of restless children who ask their grandfather for a bedtime story.  Instead, Grandpa tells the children a secret: when we sleep, we speak the same language of everyone, everywhere – the language of "Z".  When the children realize that this means that they can communicate with anyone they can think of, their imaginations run wild with the possibilities.