Resolving to wait till midnight, when all the inhabitants of the town most probably would be asleep, and when, with more security, he could make a reconnaissance of the isle and the barbican wall, the earl guided his boat into the narrow little fissure, which is one of many that perforate the island. While endeavouring to prevent its jarring on the flinty rocks, he was greatly alarmed by perceiving a human figure spring off a shelf of the volcanic wall, and plunge heavily into the deep dark water of the chasm, which penetrated, he knew not how far, into the heart of the island, but which, as it receded, became more appalling by its utter obscurity and subterranean character. Incident to the age, rather than the man, the earl's supernatural fears of kelpies, gnomes, and water-spirits, now became altogether secondary to the dread of having been discovered by some human denizen of the place. He felt for his poniard, and paused. Behind him yawned the pointed arch of the cavern, with the distant sea-beach shining in the moonlight; before him lay rocks and water buried in darkness. He lingered, oar in hand, scarcely daring to breathe, but heard only the ripple of the rising tide as it chafed on the walls of the chasm. Suddenly, another sound smote his ear, that as of a diver rising to the surface; then came a hard breathing on the water, and the regulated plashing as of some one swimming away into that very obscurity which the earl's eyes ached with regarding, but failed to penetrate. His hair bristled, and his heart quailed with momentary terror of a spirit, or evil thing; but from that very terror he gathered a courage, and, by his oar and hands, feeling the rocks on each side, shot further in his sharp-prowed boat, intent on overtaking the swimmer, and discovering whether it was a man or devil; but he had not gone twenty yards when the chasm terminated in a sheer wall of rock; and again he paused to listen. The dash of the water had ceased. He thought he heard other sounds, like those of footsteps clambering up the rock; but feared he was mistaken, for all became immediately still, and he heard only the murmur of the water as it boiled among the reefs without. "Tush!" thought he, reddening with shame at his own alarm; "it has only been some poor seal or sea-dog basking on the rocks in the summer moonlight. By midnight the moon will be in the west--till then let me sleep, for these last two nights I have never closed an eye;" and looping a rope round a pinnacle of rock, he securely moored the boat, and reclined within it to sleep. Such was the effect of the weariness oppressing him, that in three minutes he was buried in profound slumber, rocked by the motion of the boat, which gently rose and fell on the undulations of the water; for though around the isle the swell was heavy, the waves being broken by the jutting of the rocks at the cavern mouth, they rolled gently and smoothly into its dark recesses.