Please tell me said Helen. She put her hand on Sherlock Holmes's arm. I must find out more before I tell you, Miss Stoner. Now goodbye, and don't be afraid," replied Sherlock Holmes We walked to the village, and Holmes said to me, Tonight will be dangerous, Watson. Roylott is a very violent man. But if I can help, Holmes, I shall come with you," I said Thank you, Watson. I'll need your help. Did you see the bell-rope, and the air-vent? I knew about the air- vent before we came. Of course there is a hole between the two rooms. That explains why Helen's sister could smell Dr Roylott's cigarette.' "My dear Holmes! How clever of you!' I cried. And did you see the bed? It's fixed to the floor. She can't move it. It must stay under the rope, which is near the air-vent.' Holmes!' I cried. "I begin to understand! What a terrible crime! "Yes, this doctor is a very clever man. But we can stop him, I think, Watson