There could be so little doubt, after that, concerning such words as "Under," "High," "Important," and "Water," which supplied the characters, U, G, M, P, W, and O, which was also suggested in "Or," before "Haunted," that a bit of additional substitution very promptly cleared the entire affair.

Grenville jotted it down, to make sense, in the following fashion:

"Under tree, Three-Hill, or Haunted Island, Cave. Get in (during) high water (in) Spring time when noise loud. Important. Make no mistake. Map on Buli shows same."

The one word which he felt to be doubtful was "Buli," which, he confessed, might as readily be "Zuli," "Juli," or "Quli," but this was of no significance, one way or another. Its meaning was still obscure.

There were several things in the message or statement, however, that confirmed his earlier uneasiness. The principal of these was the statement that it was important for the possible seekers of some cavern under the greater wall of rock to visit the island only during the time when the hideously haunting sounds were at their height. This argued, he thought, that the sounds would finally subside, or altogether cease, when complications—doubtless in the form of visitors—might be expected to develop.

That the visitors would be natives and, probably, Dyaks, Grenville could have no doubt. As to what there was in the cave beneath the rock, he had small curiosity only, since it was hardly likely such tools as he desired would be so concealed from a prying world, and tools alone had value for him now.

He could not doubt, however, that something there was in the cave here described, for which men had risked their lives. He thought of the headless skeletons, and then of the mummy in chains.

Suddenly, at thought of that guardian of the barque, his heart gave an added leap. He snatched from his pocket the parchment referred to as a map. He could instantly see, by the light of day, that the leathery substance was leather, indeed, of the most grewsomely repellent description! It was simply tanned human skin!

And abruptly he understood that phrase—"Map on Buli shows same." The pyramids represented the island's three great hills, and other signs the cave. The pole with a knob, on the tallest hill, was the tree so near his camp.

Aye, the thing was a map in very truth—and once it had been ON Buli! For Buli was he who sat in the barque, chained fast to prevent his escape!