When young Henry Atherton helps Mr Fogarty clean up his house, he expects to find a mess and a cranky old man; what he doesn't expect to find is Pyrgus Malvae, crown prince of the Faerie realm, who has escaped the treacherous Faeries of the Night. A demon prince, greedy glue factory owners Brimstone and Chalkhill, and the nefarious Lord Hairstreak, leader of the Faeries of the Night, all dream of ruling the Faerie realm and are out to kill Pyrgus. Enlisting the help of his new friend Henry, Pyrgus must get back to the Faerie world alive before one of his many enemies gets to him...