But Bob was obdurate. "You've been wearing yourself out these last few days," he said simply. "You can surely trust me to fill your place for the first half of the night, at least. Perhaps I may not need to call you, for I know I couldn't sleep if I tried. My brain is buzzing with odd ideas, which would be bound to keep me awake."
The elder man hesitated for a moment, then gave in. "But promise to call me at one o'clock, Bob," he said, "otherwise I'll stay up with you;" and Bob promised.
A few minutes and a row of sleeping figures lay outstretched around the fire. Bob tightened up his cartridge-belt, pulled up the heads of several cartridges so that they might be easily extracted in an emergency, examined the magazine of his gun, and closed the breech gently, bringing the trigger to full cock. Then he waited, motionless as a statue, beside the huddled forms of his comrades, with rifle upraised, and every nerve strung at highest tension. Well he knew that danger threatened; he felt it in the air; an ominous calm prevailed; how soon would it be broken by the savage yells of the guardians of the mountain? Bob gripped his rifle the tighter, and his eyes scanned the near distance critically, then roamed aloft to the now deserted mountain summit. A slight sound startled him, and his finger closed gently on the trigger of his weapon, but it was only Mackay tossing restlessly in his blanket. Bob looked pityingly at the sleepless form, and at that moment Mackay beckoned him.
"I canna get it out o' my mind," he whispered, "that when I followed the tracks o' the blacks, they led right into the mountain an' no' round about it, an' it beats me to know how they managed to climb over so quickly. Keep a careful watch, Bob; keep a careful watch."
Bob nodded silently and returned to his position. He had unconsciously shared Mackay's fears before they had been spoken. Since he first saw the mysterious mount he had marvelled how it had been scaled, and how descents had been accomplished.
The Southern Cross slowly sank to rest, and the edge of the Great Bear constellation peeped above the northern horizon. Yet still the watcher stood erect at his post, and the camp slumbered.
CHAPTER XIV The Struggle by the Mountain
It was well after midnight, and Bob still stood guard over the sleeping camp with undiminished vigilance. Not a sound in the air escaped him; he heard the distant scream of the curlew with a shiver of dread, then nearer at hand the dull monotone of a mopoke resting on some rocky ledge overhead would reach his ears as a dismal calling from a shadowy world. Again would come a period of silence, broken only by the gurgling echoes from the sulphur springs, and the regular breathing of the sleepers. Bob pulled himself together impatiently, he had felt himself relaxing into a kind of stupor wherein all things grim and melancholy appeared to him.