Krondor: Tear of the Gods (Riftwar Legacy Series #3)

The vile sorcerer Sidi plans to strike the kingdom a fatal blow, setting the murderous pirate Bear upon the high seas in pursuit of the vessel that is transporting Midkemia's most holy object; the Tear of the Gods. From this miraculous stone all magic power is believed to flow. And if the Tear becomes the mage's trinket, the future will hold only terror, death and unending night. For Squire James, Lieutenant William, and the able magician Jazhara, the race is on to rescue the remarkable art...