"Oh, I am willing enough," I answered. "But may I ask what you are going to do with me?"
Lord Chelsford smoked in silence for several moments.
"Mr. Ducaine," he said, "who is there in the household of the Duke who opens that safe and copies those papers? Who is the traitor?"
"God only knows!" I answered. "It is a hopeless mystery."
"Yet we must solve it," Lord Chelsford said, "and quickly. If a single batch of genuine maps and plans were tampered with, disparities would certainly appear, and the thing might be suspected. Besides, upon the face of it, the thing is terribly serious."
"You have a plan," I said.
"I have," Lord Chelsford answered calmly. "You remember Grooton?"
"Certainly! He was a servant at Braster."
"And the very faithful servant of his country also," Lord Chelsford remarked. "You know, I believe, that he was a secret service man. He is entirely safe, and I have sent for him. Now I imagine that the Duke will wish our new secretary to live still at the 'Brand'—he preferred it in your case, as you will remember. Our new secretary is going to be my nephew. He is very stolid and honest, and fortunately not a chatterbox. He is going to be the nominal secretary, but I want you to be the one who really does the work."
"I am afraid I don't understand!" I was forced to admit.