nice gentleman at the big house, eh? Did he seem to think that it was worth the money?'
"Jake shook his head. 'No, he was angry and said I must have learnt it wrong. He said he wanted to hear the last song that was in that book,' and he pointed to the large note-book in which I entered the results of my experiments.
"A wave of relief swept over me as I realized that the fool had not yet betrayed the secret; yet he must now know the final and ultimate formula, for he had just repeated it to me. But the explanation was not far to seek: he had taken another look at the book and memorized the last formula since he had returned that evening. So far, my secret was safe; but how long would it remain so after Jake had paid another visit to the ’big house'?
"That visit must be prevented at all costs. But how? If he chose to quit the house that minute, I had no power to stop him, How could I ensure the silence of a creature of such mentality unless I silenced him for ever? For ever! I felt myself trembling as a thought flashed through my mind as a blinding electric flash traverses a vacuum tube. Within the reach of my arm was a phial containing a liquid preparation of the deadly formula. So far it had never been tried on a living organism, but here—forced on me by circumstances over which I had had no control—was the opportunity to test its efficiency in a practical manner and at the same time ensure the silence of the only man likely to betray it to the enemy.
"Averting my head lest my very expression should betray the sinister project I had in mind, I addressed Jake: 'When have you arranged to see the kind gentleman again?' I asked as carelessly as I could.
"'Tonight, after supper,' he answered, and with those words he sealed his own fate.
"There could be no turning back now; one man must be sacrificed in order that humanity might be spared a scourge such as has never fallen on it since the world was evolved. What was one single life—and such a life!—compared with the millions of clear-minded, sentient beings who would dissolve in smoke and flame if he were allowed to reach the big house that night? During the hour which elapsed before supper-time I probed my soul as I had never probed it before, weighing the matter, sifting each argument for or against, as meticulously as did any judge before assuming the black cap. I shrunk from my task with horror, but I went through with it to the bitter end.
"Its actual accomplishment was simplicity itself. A few drops of the colorless liquid poured into the mug of cider that he always drank at supper, and the thing was done. It only remained to get him well away from the house without delay.
"'Your friend will be waiting for you, Jake,' I reminded him.
"'Aye, so he will.' He rose and took up his cap. 'Good-night, sir.'
"'Good-bye, Jake,' I answered, adding under my breath, 'and God help you!'
"I allowed him five minutes' start, then hurried on my overcoat and followed. Outside, the night was dark and forbidding, with the sky overcast by a murky veil of cloud which shrouded the face of the moon. Before me stretched the Moor, a waste of empty blackness, devoid of even a film of low-lying mist to denote the winding combes which ran between the rocky tors. As I made my way along the well-defined track I seemed to be walking through an infinity of shadows.
