Faerie Wars by Herbie Brennan
Henry thinks he is simply saving a butterfly from being eaten by Mr Fogarty's cat - but he is in fact saving the life of a misdirected exiled fairy prince. A prince who has to get back to his own land in order to thwart a threatened attack by the Faeries of the Night. But time is against Pyrgus Malvae and soon he is relying on Henry and Mr Fogarty not just to get him home but also to solve the puzzle that surrounds his exile. A wonderful, gripping, page-turning read full of the kind of detail that will ensure that this fabulous fantastic novel will have readers young and old holding their breath as the story unfolds.