“Then I shall certainly come.”

“It is very kind of you.”

“You speak of danger. You have evidently seen more in these rooms than was visible to me.”

“No, but I fancy that I may have deduced a little more. I imagine that you saw all that I did.”

“I saw nothing remarkable save the bell-rope, and what purpose that could answer I confess is more than I can imagine.”

“You saw the ventilator, too?”

“Yes, but I do not think that it is such a very unusual thing to have a small opening between two rooms. It was so small that a rat could hardly pass through.”

“I knew that we should find a ventilator before ever we came to Stoke Moran.”

“My dear Holmes!”