Otherworld Bureau of Investigation

From the back cover:
“All Atlantis seek the Jewel of Dunamis, which legend claims can overcome any enemy. Grayson James, human agent of the ultra-secret Otherworld Bureau of Investigation, has orders to keep it from the wrong hands—or destroy it. What he doesn’t know is that Jewel is a woman, not a stone! But once he meets this precious gem, destroying her is the last thing on his mind…