"You are aware, Mr. Setter, that I am under the necessity of leaving London to-night, to attend the trial of Potts and Cameron to-morrow."
"As a witness for the Crown. I am, your grace."
"I shall get back to London as soon as possible. In the meantime, I wish you to pursue your investigations with the utmost diligence, sparing no expense. Report in person every morning and evening to Lady Belgrade in this house, and by telegraph to me at Lone, in Scotland. Use great discretion in wording your telegrams. Avoid the use of names, or titles, or, in fact, any terms, in referring to the duchess, that may identify her. I hope you understand me?"
"Perfectly, your grace. I also understand how to speak and write in enigmas. It is a part of my profession to do so," answered Mr. Setter.
The duke then drew out his portmonaie, opened it, selected two notes of fifty pounds each and put them in the hands of Setter, saying:
"Here are one hundred pounds. Spare no expense in prosecuting this search. Draw on me if you have occasion."
The detective bowed.
At the same moment the footman re-entered the room, bringing a card on a silver waiter, which he handed to the duke.
The duke took it and read:
"Your grace surely forgets that, as the husband of the heiress, you are the absolute master of the house, and your will is law here. Do as you think proper."