Sherlock Holmes and I had no difficulty in engaging a bedroom and sitting-room at the Crown Inn. They were on the upper floor, and from our window we could command a view of the avenue gate, and of the inhabited wing of Stoke Moran Manor House. At dusk we saw Dr. Grimesby Roylott drive past, his huge form looming up beside the little figure of the lad who drove him. The boy had some slight difficulty in undoing the heavy iron gates, and we heard the hoarse roar of the doctor's voice and saw the fury with which he shook his clinched fists at him. The trap drove on, and a few minutes later we saw a sudden light spring up among the trees as the lamp was lit in one of the sitting-rooms.

"Do you know, Watson," said Holmes as we sat together in the gathering darkness, "I have really some scruples as to taking you to-night. There is a distinct element of danger."

"Can I be of assistance?"

"Your presence might be invaluable."

"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!"

"Oh, yes, I did. You remember in her statement she said that her sister could smell Dr. Roylott's cigar. Now, of course that suggested at once that there must be a communication between the two rooms. It could only be a small one, or it would have been remarked upon at the coroner's inquiry. I deduced a ventilator."