'Because, between ourselves,' I went on, 'both McClure and Merril think he was poisoned.' He was silent for a few seconds, as though thinking, then he asked quite naturally, 'How could that be?' 'McClure, as you know, was an Army doctor in India,' I said. 'Well, then, if any one ought to know, he ought,' and he puffed at his cigarette; 'but what symptoms did he give of being poisoned?' I detailed Edgecumbe's condition, his torpor, and the symptoms which followed. 'Is there anything suggestive of poisoning in that?' he asked, like a man curious. 'McClure seems to think so.' 'Of course he may be right,' he replied carelessly, 'but I don't know enough about the subject to pass an opinion worth having. All the same, if he were poisoned, it is a wonder to me how he got well so quickly'; and he hummed a popular music-hall air. 'The thing which puzzles McClure,' I went on, 'and he seems to know a good deal about Indian poisons, is the almost impossibility of such a thing happening here in England. He says that the Indians have a trick of poisoning their enemies by pricking them with some little instrument that they possess, an instrument by which they can inject poison into the blood. It leaves no mark after death, but is followed by symptoms almost identical with those which Edgecumbe had. During the time the victim is suffering, there is a little blue mark on the spot where the injection was made.' I looked at him steadily as I spoke, trying to see whether he manifested any uneasiness or emotion. But he baffled me. I thought I saw his lips twitch, and his eyes contract, but I might easily have been mistaken. If he were a guilty man, then he was the greatest actor, and had the most supreme command over himself, of any one I had ever seen. 'And did you find such a mark on your friend?' he asked, after a few seconds' silence. 'Yes,' I replied, 'close to the elbow.' He showed no emotion whatever, and yet I could not help feeling that he was conscious of what was in my mind. Of course this might be pure imagination on my part, and I do not think any detective of fiction fame would have gained the slightest inkling from his face that he was in any way connected with it. Springfield took his cigarette case-from his tunic, and extracted another cigarette. 'It seems a bit funny, doesn't it? but I don't pretend to offer an explanation. By the way, will he be well enough to go back to duty when his leave is up?' 'I don't know,' I replied. 'McClure will have to decide that.' 'I should think you will be glad to get rid of him, Luscombe.' 'Why?' I asked. 'The fellow seems such an impossible bounder. Excuse me, but that is how he struck me.' 'You didn't seem to think so when you thanked him for saving your life,' was my reply.