Stoneheart (Stoneheart No. 1)

Twelve-year-old George Chapman is about to find this out the hard way. When, in a tiny act of rebellion, George breaks the head from a stone dragon outside the Natural History Museum, he awakes an ancient power. This power has been dormant for centuries but the results are instant and terrifying: A stone Pterodactyl unpeels from the wall and starts chasing George. He runs for his life but it seems that no one can see what he's running from. No one, except Edie, who is also trapped in this strange world.