Shadow Chaser (The Chronicles of Siala)

Shadow Harold, master thief, is in over his head. When he accepted the King's commission (not that he had any choice in the matter) he did not think that it would be to retrieve a legendary artefact from Hrad Spein, the many-layered resting place of ogres, elves and wizards; a place of dread, awe and immeasurable power, sealed up for centuries.