Cave of Wonders (Infinity Ring, Book 5)

"Europe is in the grip of the Dark Ages, but there is a light in the dark: Baghdad. The great city has become a center of learning, populated by scholars, merchants, and explorers from all across the known world. But danger lurks in the desert ... and Dak, Sera, and Riq must act fast to save the world's greatest library from utter destruction."--