I heard Durbin go down, then the major, and finally, the district attorney. Nothing could stay their curiosity now, not even the possibility of danger, which as yet was a lurking and mysterious one. But when a light shot up from below, and the irregular opening before me became a loophole through which I could catch a very wide glimpse of the library beneath, I found that it was not necessary for me to warn them to keep away from the hearth, as they were all clustered very near the door—a precaution not altogether uncalled for at so hazardous a moment. “Are you ready?” I called down. “Ready!” rose in simultaneous response from below. “Then look out!” Reaching for the spring cleverly concealed in the wall at my right I vigorously pressed it. The result was instantaneous. Silently, but with unerring certainty, something small, round, and deadly, fell plumb from the library ceiling to where the settle had formerly stood against the hearthstone. Finding nothing there but vacancy to expend itself upon, it swung about for a moment on what looked like a wire or a whip-cord, then slowly came to rest within a foot or so from the floor. A cry from the horrified officials below was what first brought me to myself. Withdrawing from my narrow quarters I hastened down to them and added one more white face to the three I found congregated in the doorway. In the diabolical ingenuity we had seen displayed, crime had reached its acme and the cup of human depravity seemed full. When we had regained in some measure our self-possession, we all advanced for a closer look at the murderous object dangling before us. We found it to be a heavy leaden weight painted on its lower end to match the bosses of stucco-work which appeared at regular intervals in the ornamentation of the ceiling. When drawn up into place, that is, when occupying the hole from which it now hung suspended, the portion left to protrude would evidently bear so small a proportion to its real bulk as to justify any eye in believing it to be the mate, and the harmless mate, of all the others. “It hangs just where the settle stood,” observed Durbin, significantly. “And just at the point where the cushions invite rest, as the colonel so suggestively puts it in his strange puzzle of a confession,” added the district attorney. “Replace the old seat,” ordered the major, “and let us make sure of this.” Ready hands at once grasped it, and, with some effort, I own, drew it carefully back into position. “You see!” quoth Durbin. We did. “Devilish!” came from the major’s lips. Then with a glance at the ball which, pushed aside by the seat, now hung over its edge a foot or so from the floor, he added briskly: “The ball has fallen to the full length of the cord. If it were drawn up a little—” “Wait,” I eagerly interposed. “Let me see what I can do with it.” And I dashed back upstairs and into the closet of “The Colonel’s Own.”