“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 simpler 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.”