The Lord of Kestle Mount — Jeanne Montague

The mysterious Cavalier Lord Leon Treviscoe holds headstrong Roundhead heiress Cassandra Scarrier captive in his castle, Kestle Mount. At first Cassey hates him, but her feelings change to overwhelming passion. She becomes involved in espionage for the Royalists, culminating in the rescue of Queen Henrietta Maria, wife of Charles I. Cassey's adventures take her through war-torn England as she follows Leon, determined to make him love her. Her path is beset by enemies who threaten her freedom, happiness - and even her life.