“How much do you know?” he asked at last, without raising his head.

“I saw you together last night.”

“Does anyone else beside your friend know?”

“I have spoken to no one.”

The Duke took a pen in his quivering fingers and opened his checkbook.

“I shall be as good as my word, Mr. Holmes. I am about to write your check, however unwelcome the information which you have gained may be to me. When the offer was first made, I little thought the turn which events might take. But you and your friend are men of discretion, Mr. Holmes?”

“I hardly understand your Grace.”