After reading - the true villain

I think the true villain of story was the Duke of Holdernesse. He had deep darkness.The Duke talked to Sherlock Homes to own story.

"When I was a young man. I was in love . I wanted her to be my wife . but she died. She left me this one child. and I loved him because of her. But a goverment minister cannot tell the world about a love-child like this. so to the world ,James is my young secretary, not my son"

Mr James knows that the Duke is his father.and He hate the Duchess and hates his younger son Arthur. Arthur has everything, Arther has a name. a famous father, house, money, everything. James has nothing. and he wants to be the Duke of Holderness one day. That‘s not possible. of course,but James can`t understand

And next he kidnaped his younger son Arthur with Hayes. and unhappy the German teacher followed them. so someone killed him. Hayers? James? Of couse James was a bad boy. Hayes was bad person too! But really, The cause of the kidnapping and murder was the Duke` self-defense. I think so! 

Posted for Yoko