He presently once more bent his attention on the island that rendered up never a sign.
Neither the jungle, the summits of the further hills, nor the sea that stretched interminably about them enlightened his searching eyes. Save for that night experience, it might have seemed preposterous that enemies existed in the miniature world by which they were surrounded.
He crept in his cautious manner to the crumbling edge where Elaine had seen the face. There was nothing below in the water. He could readily follow the bits of shelf and succession of pits in the wall, however, whereby a daring, barefooted native might grope his way to the summit, even in the dark. It would doubtless be possible here, he reflected, to explode a bomb against the pitted surface and break away so large a cavity as to render all future ascents impossible. But this was a task to be deferred for a time, since he had no wish to acquaint the visitors oversoon with the fact that he possessed an explosive.
When he returned to the shelter again, Elaine had waked and carried her couch to the cave. Despite the fact the hour was early and the sun only well above the ocean's rim, she declared she had rested much longer than was either wise or essential.
Yet there was nothing to do for either, now that the day was begun. Their breakfast of fruits was soon concluded, then of occupation there was none. Grenville felt it inadvisable to move about too freely on the terrace, and thereby risk betraying the fact they were only two in number. A watcher stationed on the second hill could not, as a matter of fact, examine the entire top of the terrace, or even discern its principal features, but he might ascertain decidedly too much, should they carelessly expose themselves to view.
The morning proved for Grenville another exasperation. He thought of nothing by way of labor he could advantageously perform. Their defense, though crude, was fairly complete, and could scarcely be improved. To watch the edge of the jungle, hour after hour, where never a sign was vouchsafed his vigilance, was a dulling inactivity, yet a highly essential precaution that was not to be neglected.
By noon he was fairly in a mood to seek out the island's invaders alone, to hasten some definite action. That the natives intended to starve them into a visit to the spring seemed all too obvious. Grenville felt assured, however, the water down in the cavern would suffice for their needs, if no better could be relied upon, when once their jars were empty, while gathering fruit would not be wholly impossible under cover of the night.
With the thought in mind that only the trail would be kept under watch by the Dyaks, he made up his mind he could readily contrive a ladder-like platform to extend from the brink, whereby the distance to the nearest tree might be conveniently bridged to permit easy access to the jungle. Of creepers and extra bamboo poles he had laid in ample stock. For the lack of better employment, he began the construction of his bridge when their meager luncheon had been finished.
His mind, as he worked, spun schemes innumerable for the daily defeat of the natives. Aware that as long as the terrace could be held starvation and thirst would be their only unconquerable enemies, he entertained no end of plans for catching fish without bait and even trapping or fishing up small animals that might rove at night below the cliff. From these reflections he returned to the men who prowled about them after dark.
To secure his cord across the trail and thereby provide an alarm, or notice of the enemy's approach, from that direction, was a very simple matter. When he finally invented, in his mind, a singular "rattle" to guard the approach by the cliff, he dropped all employment on the bridge at once and began forthwith on the other.