"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— for 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 first of criminals. He has nerve and he has knowledge. Palmer and Pritchard were among the heads of their profession. This man strikes even deeper, but I think, Watson, that we shall be able to strike deeper still. But we shall have horrors enough before the night is over; for goodness' sake let us have a quiet pipe, and turn our minds for a few hours to something more cheerful."
About nine o'clock the light among the trees was extinguished, and all was dark in the direction of the Manor House. Two hours passed slowly away, and then, suddenly,
