"Do not imagine," said Holmes, "that I depend for my success in this case upon the mere chance of one of these fellows having put his foot in the chemical. I have knowledge now which would enable me to trace them in many different ways. This, however, is the readiest and, since fortune has put it into our hands, I should be culpable if I neglected it. It has, however, prevented the case from becoming the pretty little intellectual problem which it at one time promised to be. There might have been some credit to be gained out of it, but for this too palpable clue."
"There is credit, and to spare," said I. "I assure you, Holmes, that I marvel at the means by which you obtain your results in this case, even more than I did in the Jefferson Hope Murder. The thing seems to me to be deeper and more inexplicable. How, for example, could you describe with such confidence the wooden-legged man?"
"Pshaw, my dear boy! it was simplicity itself. I don't wish to be theatrical. It is all patent and above-board. Two officers who are in command of a convict-guard learn an important secret as to buried treasure. A map is drawn for them by an Englishman named Jonathan Small. You remember that we saw the name upon the chart in Captain Morstan's possession. He had signed it in behalf of himself and his associates,--the sign of the four, as he somewhat dramatically called it. Aided by this chart, the officers--or one of them--gets the treasure and brings it to England, leaving, we will suppose, some condition under which he received it unfulfilled. Now, then, why did not Jonathan Small get the treasure himself? The answer is obvious. The chart is dated at a time when Morstan was brought into close association with convicts. Jonathan Small did not get the treasure because he and his associates were themselves convicts and could not get away."
"But that is mere speculation," said I.
"It is more than that. It is the only hypothesis which covers the facts. Let us see how it fits in with the sequel. Major Sholto remains at peace for some years, happy in the possession of his treasure. Then he receives a letter from India which gives him a great fright. What was that?"
"A letter to say that the men whom he had wronged had been set free."
"Or had escaped. That is much more likely, for he would have known what their term of imprisonment was. It would not have been a surprise to him. What does he do then? He guards himself against a wooden-legged man,--a white man, mark you, for he mistakes a white tradesman for him, and actually fires a pistol at him. Now, only one white man's name is on the chart. The others are Hindoos or Mohammedans. There is no other white man. Therefore we may say with confidence that the wooden-legged man is identical with Jonathan Small. Does the reasoning strike you as being faulty?"