“Yes,” answered Harry promptly. “I walked down to the lake to obtain a breath of air. It was chilly out; I did not remain there long.”
“I see,” replied the professor. “Notify me in the future, Vincent. We have certain rules here which every one obeys. I have told you some of them.
“One is to remain quiet after eight o’clock; for I often do important work in the evening. No radio. No going out. Each man must be on hand — except, of course, when he notifies me and receives my permission to be away.”
“Very good, sir.”
“Let me remind you,” said the professor, “that you must be careful in this house. I have chemicals and mechanical appliances which are dangerous.
“Doors that are locked are kept that way with a purpose. Those that are unlocked may have been left open through negligence.
“If anything occurs that seems to demand investigation, notify me before you proceed. You will learn everything by degrees. So be patient.”
WITH this admonition, the old man dropped the subject, and immediately became engrossed in his work.
Harry threw a hasty look in the direction of Stokes. He wondered if the man had suspected the extent of his visit outdoors, last night.
Professor Whitburn had given the matter no special consideration. He had not questioned if Harry had seen anything unusual. But perhaps Stokes was thinking on the subject.