"Now, Watson," said Holmes, rubbing his hands, "we have half an hour to ourselves. Let us make good use of it. My case is, as I have told you, almost complete; but we must not err on the side of overconfidence. Simple as the case seems now, there may be something deeper underlying it." "Simple!" I ejaculated. I looked at the round, well-defined muddy discs. "That is not a foot-mark," said I. "It is the wooden-legged man." "Quite so. But there has been someone else — a very able and efficient ally. Could you scale that wall, Doctor?" "It is absolutely impossible," I answered. "What then?" I asked.