Feisty Chicago heiress, Evangeline "Birdie" Horst, wants nothing more than to make her debut in London, yet her family drags her on a detour through the Lake District. While visiting the ruins of a stately castle, Birdie meets a handsome and mysterious groundskeeper who endeavors to show her the beauty of the English countryside.

As a young boy, the Duke of Rosthwaite lost his home in a devastating fire. Determined to keep the estate from falling into further disrepair, he lives and works on the grounds of Keswick Castle, which he opens to paying visitors during the summer. While laboring in the gardens, Ross meets a bold American beauty set to inherit a fortune and insistent on marrying an English nobleman.

Marriage to a Dollar Princess would solve his money problems, yet Ross knows the true cost of life in the aristocracy. Can he convince Birdie that he isn't a predatory peer before she soars from his life forever? Or will the Duke and Duchess of Rosthwaite become trapped together in a gilded cage of their own making?