Minute by minute, as they waded through that death-white wilderness, the moon wove the cloud-shroud into thinner veils, till at last, as the two figures emerged upon the shore by the side of a precipitous scaur, they were of a filmy gossamer that no longer obscured the golden-yellow globe that wheeled solemnly through the appalling upper solitudes of the night. The tide, at the last reach of the ebb for nearly an hour past, was now on the flood: though the first indeterminate babble of returning waters was scarce different from the lapsing ebb-music in aught save a gurgling swiftly repetitive undertone. The scaur by whose side they stood was hollow, and was known as the Cave of the Sea-Woman. It could be reached dry-shod, or nearly so, only at low-water, and even then only during calm, or when the wind did not blow from the south or west. For years beyond record it had been almost unvisited, for the cavern was a place of deadly peril except just before and after the extreme ebb. But after the death of two of his sons--one in the effort to swim outward against the inrush of the tide; the other by falling, or being swept backward to the deep chasm that lay at the far end of the cave--old Macrae, of Ardfeulan Farm near by, had caused rude steps to be cut in the funnel-like hollow rising sheer up from the sloping ledge that lipped the chasm and reached the summit of the scaur. The smell of the brine from the dripping boulders smote shrewdly upon Alastair and Lora as they stood at the weedy mouth of the cavern. Then for the first time that night they turned their backs upon the sea, and moved slowly across the long, flat slabs of rock. It was not dark at the entrance to the Cavern of the Sea-Woman, for the moonlight moved within it as the hand of a blind man groping blankly in an unfamiliar place. The arch of the rock was clear, and even the frondage of fern and sea-plants suspended from its lower curve; also, beneath, a mass of mossed crag, just beyond the highest reach of the tides. Among this dark crag-vegetation grew strange plants; but none stranger or so rare as the sea-grape, or mermaid's-fruit of the islanders. No one on Innisròn knew its proper designation, and it had become known at all as the sea-grape only because some student of rare things discovered and wrote about it under that name, as perhaps the culminating treasure-trove of the botanist in the Scottish West. It is a plant which clings as a tendril, choosing only the summit of high rocks or boulders in some sunless place where it can breathe the ooze from dead or dying sea-weed, and can feel the salt air reach it with a chilly touch. It lies low, with its thin, moist, ash-grey stems; its round, pale-green, transparent leaves faintly spotted with livid blotches; and its infrequent clusters of small, juicy berries of a hue of dusky yellow.