It was only a matter of minutes, but it seemed to be hours before the band of men began to move forward cautiously through the darkness, and more than ever the professor blamed himself for not staying with his friends, but only to acknowledge the next moment that if he had done so he would not have known of the approach of the foe.
As near as he could judge the enemy had about half a mile to go, and not knowing what to do Mr Preston began to follow them cautiously, getting as near as he could while straining his eyes to make out the figures of the mounted men as they moved slowly on.
By degrees he found out that he was left a long way behind, but while quickening his pace he was compelled to do so with the greatest caution, and to walk with outstretched hands, for, though high above his head the starlight enabled him to make out the line of the high cliff against the sky, all below in that gorge was of pitchy blackness, and he had to guide himself by stepping carefully more than by the use of his eyes.
In spite of his care he was, he found, being left more and more behind, and yet he dare not hasten for fear of coming suddenly upon the rear of the party.
But at last, quite in despair, he pressed forward, trusting to his good fortune to get near enough to note their actions without being detected, so that at last he was within a very few yards, and he kept that distance till he felt that they must be very near the spring, when, as he pressed on, keeping to the path, as he believed, he suddenly found himself about to stumble over a low block of blackish stone just beneath his feet.
He tried to save himself, but he was too late, and he blundered right upon it; but instead of knocking the skin off his shins, and falling heavily, he was stricken back, for the object he had taken for a rock felt soft, sprang up, and he found, as the man, who had been stooping to bind up his rough gear, uttered a few angry words in his own tongue, that he had come upon a laggard of the party.
It was evident that in the darkness the man imagined that he was addressing a companion, for he gripped the professor fiercely and whispered a question.
A struggle would have ensued, but just then a clear voice rang out on the night air, sounding wild and strange, and echoing from the face of the cliff as it seemed to cut the black darkness.
The man dropped the professor’s arm which he had seized, sprang away into the darkness ahead, and then there was utter silence.