When a rifle is fired downward from a great height, what is known as the "trajectory", or flight, of the bullet is affected, and in consequence the line of sight is not wholly accurate. This may have been sufficient to account for the failure of the Arab's shot; but in any case, to put a bullet within an inch of the target at so great a range proved him a marksman of the greatest skill.
When he saw that he had missed he hurried on his way, hoping against hope to reach the spur in advance of Harry Urquhart.
The boy was determined that the fugitive should not escape. He cared little or nothing for the life of Bayram, but at all costs he meant, if possible, to recover the Sunstone. He was never able to forget that, all this time, von Hardenberg was shut up alive in the silent vault, in the very heart of the mountain.
Running as if his life depended on his efforts, he dashed down the valley. Three times the Black Dog fired, and each time the bullet flew within a hand's-breadth of its mark.
On gaining the spur, Harry clambered to the southern side, where he was out of sight of the fugitive, who was now too far away to fire. Slinging his rifle across his shoulder, hand over hand the boy climbed up the rocks, and at last gained the pathway which formed a little ledge, or terrace, upon the face of the great abyss.
He walked forward stealthily. On his right hand a rock arose, inaccessible and smooth as a plate of steel, whilst on the left it dropped sheer into the shadowy depths of the valley from which he had come. Far below him, the stream that he had followed looked like a little silver thread glittering in the sunlight.
He knew that he must find some kind of cover. If he came face to face with Black Dog on that narrow path he would have little chance of living. A rifle in the sheikh's hands, at a point-blank range, was more an implement of execution than a weapon of defence; and, besides, the Black Dog was known to be a man of prodigious strength.
As the boy went upon his way he looked forward eagerly, hoping to find some rock or boulder behind which he could hide and await the approach of the Arab. But the path was bare, not only of vegetation, but of stones and fragments of rock. It was as if some mighty hurricane had swept the mountain-side, brushing all obstacles from the narrow ledge, sweeping the place as clean as the pavement of a street.
Presently the path turned a sharp angle. The cliff stood folded back in the shape of the letter W. From the corner, Harry was able to see, not only the other extremity of the W, but also the smaller salient which formed the centre of the letter. It was then that the complete success of their enterprise was made apparent.
At the corner of the southern extremity was Harry, and at the northern stood the guide, his rifle in his hand. Between them the face of the precipice was folded back in two re-entrant angles. Everywhere the abyss was smooth and perpendicular, both above and below the pathway. It was possible to climb neither up nor down. Escape was beyond all question. And midway between Harry Urquhart and the half-caste guide, standing upright at the central angle, was Sheikh Bayram, the Black Dog of the Cameroons, like a great bird of prey perched above its eyrie. Whatever the issue of this business was to be, it was certain that for the present the fugitive was caught.