on, 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 maint