Queen of the Castle follows Canadian socialite Ann Kaplan Mulholland and her husband Dr. Stephen Mulholland as they take on the ambitious task of turning their newly acquired medieval castle in the heart of Kent, U.K. into a luxurious world-class destination. With $40 million of their own money on the line, they face the daunting task of navigating construction, staffing, local skepticism, and demanding guests as old tradition meets modern chaos.