Wizard's Daughter by Catherine Coulter (2007, Paperback)

Catherine Coulter does it again with this well written time piece of intrigue and romance set in England.
Ryder Sherbrooke finds a child half beaten to death in an alley and takes her home to raise with his own son. Now Rosalind is a beautiful young woman who rarely speaks of her ordeal. It's only when she meets Nicholas Vail, the Earl of Mountjoy, at her London debut, is she certain that he has an important role to play in her destiny. Nicolas and Rosalind are drawn to each other instantly and together they find a mysterious book written in a baffling code that nobody but Rosalind can read. At this point, strange things begin to happen and both of them realize it has to do with this book and perhaps even Rosalind's haunting past. As the suspense builds near the end of the book, you realize that Rosalind could be the key to a centuries old mystery.

I love it when Ms. Coulter steps aside from her thrillers and puts her heart and soul into something as good as this romance mystery from the past.