Krondor: Tear of the Gods : Book Three of the Riftwar Legacy

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 artifact. For all manner of dark creatures are gathering with one unspeakable purpose: to breed the chaos that will hasten the destruction of Squire James and his brave companions . . . and bring about the total corruption of the Tear of the Gods.