"Well, good luck to you," said the grim Scot, "and let me likewise warn all hands not to be too astonished if we find that the treasure is not in the cave. But I'll admit it is as good a place as any for beginning the search, and there will be none gladder than I if it turns out that I was no judge of the workings of Captain Sampson's mind." The cave which was now the center of our hopes--I say our, because somehow or other I found myself hoping and fearing along with the rest, though carefully concealing it--ran under the point at its farther end. The sea-mouth of the cave was protected from the full swell of the ocean by some huge detached rocks rising a little way offshore, which caught and broke the waves. The distance was about sixty feet from mouth to mouth, and back of this transverse passage a great vaulted chamber stretched far under the land. The walls of the chamber rose sheer to a height of fifteen feet or more, when a broad ledge broke their smoothness. From this ledge opened cracks and fissures under the roof, suggesting in the dim light infinite possibilities in the way of hiding-places. Besides these, a wide stretch of sand at the upper end of the chamber, which was bare at low tide, invited exploration. At high water the sea flooded the cavern to its farthest extremity and beat upon the walls. Then there was a great surge and roar of waters through the passage from mouth to mouth, and at turn of tide--in hopeful agreement with the legend--the suck and commotion of a whirlpool, almost, as the sea drew back its waves. Now and again, it was to prove, even the water-worn pavement between the two archways was left bare, and one could walk dry-shod along the rocks under the high land of the point from the beach to the cave. But this was at the very bottom of the ebb. Mostly the lower end of the cave was flooded, and the explorers went back and forth in the boat. A certain drawback to boating in our island waters was the presence of hungry hordes of sharks. You might forget them for a moment and sit happily trailing your fingers overboard, and then a huge moving shadow would darken the water, and you saw the ripple cut by a darting fin and the flash of a livid belly as the monster rolled over, ready for his mouthful. I could not but admire the thoughtfulness of Mr. Tubbs, who since his submergence on the occasion of arriving had been as delicate about water as a cat, in committing himself to strictly land operations in the search for Bill Halliwell's tombstone. Owing, I suppose, to the stoniness of the soil, the woods upon the point were less dense than elsewhere, and made an agreeable parade ground for Mr. Tubbs and his two companions--for he was accompanied in these daring explorations with unswerving fidelity by Aunt Jane and Miss Higglesby-Browne. Each of the three carried an umbrella, and they went solemnly in single file, Mr. Tubbs in the lead to ward off peril in the shape of snakes or jungle beasts.