For there was a sharp, grating sound as of stone against stone, and then silence. "Stand fast, every man," cried Lennox excitedly, seizing his revolver and looking along the broad, rugged shelf upon which they stood in the direction from which the sound had come. "A lantern here," cried the captain as a sharp movement was heard, and half-a-dozen men at a word from their officer doubled along the shelf for a couple of dozen yards and then stood fast, while the other end of the path was blocked in the same way. Lennox's heart was beating hard with excitement, and he started as he felt Dickenson grip his arm firmly. Then all stood fast, listening, as they waited for the lantern to be brought. Quite ten minutes of painful silence elapsed before a couple of dim lights were seen approaching, the bearers having to come down from the gun-platform; and when the two non-commissioned officers who bore them approached, and in obedience to orders held them up, they displayed nothing but swarthy, eager-looking faces, and the piled-up rugged and weathered rocks on one side, the black darkness on the other. "Come this way, sergeant," said Captain Edwards, and he, as officer in command of the detachment that night, led on, followed closely by Captain Roby and the two subalterns. They went along in perfect silence, the lanterns here being alternately held up and down so that the rugged shelf and the piled-up masses of rock which formed the nearly perpendicular side of the kopje in that part might be carefully examined. This was done twice over, the party passing each time where their men were blocking the ends of the shelf which had been selected for one of the posts. "It's strange," said Captain Roby at last. "I can see no loose stone." "No," said Captain Edwards. "It was just as if a good-sized block had slipped down from above. Let's have another look." This was done, with no better result, and once more the party stood fast in the dim light, gazing in a puzzled way. "Can any one suggest anything?" said Captain Roby. There was silence for a few moments, and then Lennox caught hold of Dickenson's arm and gave it a meaning pressure as he turned to the two captains, who were close together. "I have an idea," he whispered. "Give the orders loudly for the men to march off. Take them round to the south, and wait." "What for?" said Captain Roby snappishly. "I should like Dickenson and me to be left behind. I'll fire if there is anything." "Oh, rubbish!" said Captain Roby contemptuously. "No," said his brother officer quietly. "It is worth trying." Then turning to the two sergeants who bore the lanterns, he said, "When I say put out those lights, don't do it; cover them sharply with greatcoats." Directly after he gave his first order, when the lanterns rattled, and all was dark.