Peter is a young boy that, after an unfortunate incident with his sister, ends up in the Overworld - a secret place on top of the clouds. The Overworld is under threat from a sinister general who has seized power and seeks to stop all rain. Peter must find the heir to the throne, stop the general and make sure that it rains again - but most of all he wants to find a way home.

This book is the first in a series of books. It is followed by "Winter clouds".