"I had no keys of the doors--only of the safe."

"Was Sir James a man who was orderly in his habits?"

"Yes, I think he was. I know that so far as those three keys are
concerned he kept them on the same ring. I have often seen them
there."

"And that ring went with him to London?"

"He said so."

"And your key never left your possession?"

"Never."

"Then West, if he is the culprit, must have had a duplicate. And
yet none was found upon his body. One other point: if a clerk
in this office desired to sell the plans, would it not be simply
to copy the plans for himself than to take the originals, as was
actually done?"

"It would take considerable technical knowledge to copy the plans
in an effective way."

"But I suppose either Sir James, or you, or West has that
technical knowledge?"

"No doubt we had, but I beg you won't try to drag me into the
matter, Mr. Holmes. What is the use of our speculating in this