Icefire ( The Last Dragon Chronicles #2) by Chris D'Lacey-Used

In this exciting sequel to The Fire Within, David must uncover the truth behind the mysterious clay dragons. David's quest is to discover the link between the fire of the last known dragon on earth and the icy regions of the Arctic. It's a journey that will change his life forever, a journey that will bring him to the very heart of the legend of dragons and the mysterious, ancient secret of the icefire...