Destiny - The Immortal Witches, #3

"Intense, mystical and lyrical, " raves Library Journal, calling New York Times Bestseller Maggie Shayne "one of romantic fantasy's most accomplished authors."Nidaba, the high priestess he adored, had supposedly died in a fire more than four thousand years ago. But when the one-time King of Sumer, Eannatum, now living a quiet life as modern Nathan King, sees her photo in a newspaper, he has to know for sure.
He finds the once powerful High Priestess of Inanna in a locked mental unit, catatonic and alone. But when he breaks her out, taking her to his peaceful haven to make her well again, he doesn't know that the dark one who tore them apart long ago is watching, or that he is putting his new life, and all those he loves, at terrible risk. If you read and loved ETERNITY and INFINITY, books 1 and 2 in this series, you must have the third tale