The Dream Hunter (Dream-Hunter, #2; Dark-Hunter, #10)
What she doesn't know is that Arik holds more than the ancient secrets that can help her find the mythical isle of Atlantis. He has made a pact with the god Hades: In exchange for two weeks as a mortal man, he must return to Olympus with a human soul. Megeara's soul.
With a secret society out to ruin her expedition, and mysterious accidents that keep threatening her life, Megeara refuses to quit. She knows she's getting closer to Atlantis and as she does, she stumbles onto the truth of what Arik really is.
For Arik his quest is no longer simple. No human can know of a Dream-Hunter's existence. His dream of being mortal has quickly turned into his own nightmare and the only way to save himself will be to sacrifice the very thing he wanted to be human for. The only question is, will he?