"Well, you see, he first finds out that I am returning by a late train—which he seems to have done—and he waits for me at the terminus. Meanwhile he fills the cylinder with a solution of a powerful alkaloidal poison, which is easily done by dipping the needle into the liquid and sucking at the small hole near the back end, when the piston will be drawn up and the liquid will follow it. You notice that the upper side of the piston is covered with vaseline—introduced through the hole, no doubt—which would prevent the poison from coming out into the mouth, and make the cylinder secure from leakage. On my arrival, he follows me on his bicycle until I pass through a sufficiently secluded neighbourhood. Then he approaches me, or passes me and waits round a corner, and shoots at pretty close range. It doesn't matter where he hits me; all parts are equally vital, so he can aim at the middle of my back. Then the bullet comes spinning through the air point foremost; the needle passes through the clothing and enters the flesh, and, as the bullet is suddenly stopped, the heavy piston flies down by its own great momentum and squirts out a jet of the poison into the tissues. The bullet then disengages itself and drops on to the ground.
"Meanwhile, our friend has mounted his bicycle and is off, and when I feel the prick of the needle, I turn, and, without stopping to look for the bullet, immediately give chase. I am, of course, not able to overtake a man on a racing machine, but still I follow him some distance. Then the poison begins to take effect—the more rapidly from the violent exercise—and presently I drop insensible. Later on, my body is found. There are no marks of violence, and probably the needle-puncture escapes observation at the post-mortem, in which case the verdict will be death from heart-failure. Even if the poison and the puncture are discovered, there is no clue. The bullet lies some streets away, and is probably picked up by some boy or passing stranger, who cannot conjecture its use, and who would never connect it with the man who was found dead. You will admit that the whole plan has been worked out with surprising completeness and foresight."
"Yes," I answered; "there is no doubt that the fellow is a most infernally clever scoundrel. May I ask if you have any idea who he is?"
"Well," Thorndyke replied, "seeing that, as Carlyle has unkindly pointed out, clever people are not in an overwhelming majority, and that, of the clever people whom I know, only a very few are interested in my immediate demise, I am able to form a fairly probable conjecture."
"And what do you mean to do?"
"For the present I shall maintain an attitude of masterly inactivity and avoid the night air."
"But, surely," I exclaimed, "you will take some measures to protect yourself against attempts of this kind. You can hardly doubt now that your accident in the fog was really an attempted murder."
"I never did doubt it, as a matter of fact, although I prevaricated at the time. But I have not enough evidence against this man at present, and, consequently, can do nothing but show that I suspect him, which would be foolish. Whereas, if I lie low, one of two things will happen; either the occasion for my removal (which is only a temporary one) will pass, or he will commit himself—will put a definite clue into my hands. Then we shall find the air-cane, the bicycle, perhaps a little stock of poison, and certain other trifles that I have in my mind, which will be good confirmatory evidence, though insufficient in themselves. And now, I think, I must really adjourn this meeting, or we shall be good for nothing to-morrow."