Howland Know The Truth

"I'll leave you so you can think for a moment," Duke Coby said, then left Howland alone.

How could Duke Coby know everything just by sending one person to the palace? He frowned. And, who was that person? Why didn't he know about this before? Did Duke Coby send that person with the permission of his father or mother?

Now all the questions and doubts that he initially imposed on Rosie and Aslan now turned to his own uncle. 

Before he lost his mind, Howland tried to think clearly with his logic. His uncle said he was sick, but why did the man still look so healthy, and there was absolutely no sign that he was sick? If what his uncle said was true that the soul in his sister's body right now was another woman, then how could Duke Coby know all of that in such detail?

As far as Howland knew, only people who could perform black magic knew all these things because so far all knowledge related to black magic had been banned all over the world.