"We’d have to create a sort of defensive mind fort," Harry considered thoughtfully. "Enola might have an idea about how to do that. It wouldn’t be a new mind plain, but it would a sort of first line of defence for my subconscious. There might be a way to attack or deflect any incoming signal trying to penetrate my mind ... even your signal, in case the enemy finds a way to piggy back on it. Narcissa could help there."