The only sounds which broke the eery stillness were the slight crunching of the gravel beneath my hurrying footsteps and the far-off mournful cries of a flock of wandering sea-gulls.
"When the slope of the ground told me that I had passed the brow of the ridge, I glanced at the illuminated dial of my watch and saw that twenty minutes had elapsed since I had administered the drug to Jake. This told me little, for I had not the slightest idea how long the stuff would take to work. I walked more slowly down the slope, and only quickened my pace to mount the farther side of the combe in order to get a view of the path ahead. Not that I could see anything in that pall of darkness as yet, but I wanted to have an uninterrupted view of what was about to happen. Of course, I had not caught sight of Jake since quitting the house, but I knew that the path I had followed was the only means of his reaching 'the big house.' Somewhere in the darkness ahead he must be hurrying along, his poor brain filled with childish delight at the prospect of soon possessing another big, shining coin; as blissfully unconscious of his impending fate as are the microscopic infusoria before the drop of sterilizing solution wipes them out of existence.
"At last I reached the summit of the high tor from which I knew I could command a view almost to the gates of the house for which Jake was making. I paused and glanced at my watch again. I started when I saw that a full hour had elapsed without anything happening. Had the experiment failed? Was the whole thing nothing but an empty, impracticable dream? Had my days and nights of labor been wasted in a quest as useless and futile as those of the madman who strove to square the circle or evolve a system of perpetual motion? Throwing aside all caution in my desire to know what had happened, I pressed onward almost at a run. Nor did I pause or slacken speed when my onward progress brought into sight a single pinpoint of light, telling me that the inmates of the Sanatorium were awake and stirring.
"Then, slowly but inexorably, the conviction was forced on me that my experiment had failed—that, though theoretically flawless, it had proved useless when subjected to the acid test of practise—and I can truthfully say that my first emotion was a feeling of profound relief.
"'Thank God, the formula is harmless!' I cried, and laughed aloud in the darkness. 'Let him tell the spy the secret—and much good may it do him! I have failed—but again I thank God and am content. At least, humanity has been spared the menace of——'
"Coming from a spot barely a hundred yards ahead, a flash of blood-red fire stabbed the night, and the fraction of a second later a dull, muffled concussion smote my ears. It was the death-knell of Crazy Jake!—that was my one conscious thought as I stood, stunned by the awful manner in which my theory had been proved. It was some minutes before I could pull myself together.
"Prudence warned me to leave the spot as soon as possible, for it was but a short distance to the spy's house and he could not have failed to hear the explosion. Yet a horrible fascination, an irresistible desire to look upon my fell handiwork, drew me onward as a magnet draws a needle. Almost before I was aware of what I was doing—the danger I was courting in risking being seen near the spot—I found myself running forward, my eyes following the dancing
