The Edge Chronicles: The Curse of the Gloamglozer First Book of Quint

Fourteen-year-old Quint Verginix is the only remaining son of famous sky-pirate Wind Jackal. He and his father have journeyed to the city of Sanctaphrax - a great floating rock, bound to the ground below by a chain, its inhabitants living with their heads literally in the clouds.
But the city hides a dangerous secret: deep inside the great rock, something horrible lurks. With his father away, Quint may be the only one who can save Sanctaphrax from the dreaded curse of the gloamglozer . . .
The Curse of the Gloamglozer is the first book of the Quint Saga - first trilogy in The Edge Chronicles, the internationally best-selling fantasy series, which has featured on the UK and the New York Times best-seller lists and sold more than 3 million copies. There are now 13 titles and four trilogies in the series, but each book is a stand-alone adventure, so you can read The Edge Chronicles in any order you choose.