“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.”


“But what harm can there be in that?”


“Well, there is at least a curious coincidence of dates. A ventilator is

made, a cord is hung, and a lady who sleeps in the bed dies. Does not that

strike you?”


“I cannot as yet see any connection.”


“Did you observe anything very peculiar about that bed?”


“No.”


“It was clamped to the floor. Did you ever see a bed fastened like that

before?”


“I cannot say that I have.”


“The lady could not move her bed. It must always be in the same relative

position to the ventilator and to the rope—or so we may call it, since it

was clearly never meant for a bell-pull.”


“Holmes,” I cried, “I seem to see dimly what you are hinting

at. We are only just in time to prevent some subtle and horrible crime.”


“Subtle enough and horrible enough. When a doctor does go wrong he is the