Embers of Atlantis - Novel by Tracy Hickman
Ethan Gallows knows plenty about the world. He knows magic exists, and he knows he wants nothing to do with it.
But when he's sent on a seemingly menial assignment to London, Ethan discovers that he has a lot more to learn. After witnessing a violent display of sorcery, the world-weary cameraman finds himself haunted by disturbing visions. Ethan must now place his trust in Sojourner - a woman claiming to be the descendant of an ancient race - and he must quickly discover the remarkable details of his own forgotten past before dark forces consume the world forever.