Inky #3: Fire in the Sea by Myke Bartlett

Sadie is bored - her unexciting summer life of lying around on the beach is getting to her, and she so desperately wants a change. Change comes stiffly though. It comes in the form of Jake - a young-looking boy who brings a whole world of danger with him. Sadie and her family are thrown into a world of Gods and their envoys - life will never be the same for Sadie.