I neared the slope to the pond, and looked down; there was nothing visible, and I began to descend with an easy stride. Although nearing the Mansion, I felt an unaccountable dread. This was the trying part of the journey, and my followers were now invisible to me, being on the plain above the crest of the hill. I gripped my revolver firmly, and stepped rapidly on to the bridge; but as I did so I heard a pistol shot from above, and knew instantly that I was in danger--that my companions had signalled me to return. I faced about, and commenced my ascent of the hill. From somewhere near a voice came to me clearly. "Run for your life," it said. I could see nothing, but retreated hurriedly, and was soon with the others at the top of the hill. "Why did you tell me to run?" I panted. They looked at me. "We said nothing," was the answer; "we merely signalled you to come back." "Well, someone ordered me to run for my life." "Ah!" said they. "We thought we heard a voice. We saw a figure at the other side of the pond. We came over the crest cautiously, and he did not expect us. He was crossing in range of the light from the Mansion gate when we detected him. So much for following you!" "Well, but who spoke to me? He could not have done so; his voice would not have sounded so near." "No, evidently someone near you was watching him; he was about to waylay you, and the watcher knew it and warned you." We heard a commotion and saw a figure dash from the bridge, away toward the north end of the pond, and disappear. Then another figure showed at the crest on the River Road and followed him at breakneck speed. "See--the man on the bridge was the fellow who warned you. The other is after him. He won't catch him, however." "Come!" I cried; and we darted down and over the bridge to the road above, but nothing was visible. Suddenly a couple of figures emerged from the darkness by the Mansion gate. We recognized Oakes and Moore, who had been awaiting us. We related the circumstances of our return to the Mansion to them. "Yes," said Oakes, "we were watching the man near the road. He had a gun, and was evidently waiting for you. We were just going to make a rush at him when we saw you run back at the signal." "Who was he?" asked I. "I will answer the question by asking: Who was the man who warned you?" "I haven't the least idea," said I. "You see, you were in great danger, and only that man's foresight saved your life. But there are _two_ unknowns now--the friend and the enemy." We watched my escorts descend and cross the bridge, mount the ascent and disappear over the crest toward Mona. Then the moonlight silhouetted their figures for an instant, as they turned and waved a farewell. _CHAPTER XII_ _The Witness_ Mr. George Elliott, aristocratic, well-to-do club-man and all-round agreeable fellow, lived in bachelor apartments on the upper West side of New York.