Finally, through the calm blue water, not more than ten or twelve feet down, we saw the mouth of the cavern where the monster had taken refuge. The palms alongshore almost overhung the lagoon at this place. The fringing reef which fell away in a line of submarine cliffs was only a few yards wide, and beyond it lay the highest land on Iriatai, the path of an ancient hurricane where the breaching seas of centuries ago had piled great blocks and masses of coral to a height of eight or ten yards above the sea. Marama dropped his paddle and took up a pair of water goggles.
"Hold the canoe here a moment," he said; "I am going overboard for a look. There was only one shark and I do not believe that a tonu would live so close to the surface."
Next moment he was over the side and swimming down toward the cave-mouth, into which I saw his body disappear. Presently, with leisurely strokes, he swam into sunlit water and rose to take breath, with a hand on the gunwale of the canoe. "Have patience a little longer," he said with a smile, as he pulled down his goggles for the second time. "I am going down once more."
Again he disappeared, and again I waited idly for his reappearance. A minute passed; a minute and a half; two minutes. I began to be alarmed. Three minutes were gone. I knew that never before had my friend stayed down so long. Four minutes—I hauled up the canoe in the shallows, snapped on my glasses and plunged down to the entrance of the cavern. As I peered in anxiously, I saw that there was a strange glimmer of light where only darkness should have been. Suddenly the light was blotted out, and Marama emerged from the tunnel and rose with me to the surface of the lagoon. When we had taken breath, his hand went up to interrupt my hasty demand for an explanation.
"Aué!" he exclaimed in an excited voice, "but that is a strange place! The hole in the coral rises as it runs inward, and seeing light ahead I thought that I would swim in a little way. The light grew stronger; all at once my head was out of water and I was breathing air. When I pushed up my glasses to look about me, I found that I was swimming in the midst of a great pool, arched over with a low ceiling of rock. At the farther end a single ray of sunlight shines through a crack between two wedged-in boulders, and beneath the light I saw a broad ledge, sandy and high above the water. On that ledge, where a hundred might stand together, are things of the old times: a heathen god, spears, stone axes, the whitened heads of men. I am afraid, but I will go back if you desire to see."
A sudden memory flashed into my mind—the scent of wood-smoke; the long, shadowy living room at home; my uncle lying in a rawhide chair with his feet against the stones of the fireplace; the missing brig; the savages of Iriatai; the story of the searching-party—beyond doubt we had stumbled on the cave where the cannibals took refuge on that day so long ago!
"There is nothing to fear in old bones," I said. "Lead the way, if you are not weary, and I will follow close behind."
Marama ducked under like a rolling porpoise, to swim down the face of the cliff with long easy strokes, and I swam after him down the cliff and into the faintly luminous gloom. The light grew stronger as we advanced; twenty yards from the entrance my head came out of water and I breathed the welcome air again. We were swimming in a black pool which half filled a long shadowy cavern, illuminated by a beam of sunlight filtering in through a cranny in the rocks. Stalactites of fantastic shape hung from the low roof, and I saw the broad ledge of which the native boy had spoken. We were in the hidden refuge of the savages, the lurking-place of the terrible carcharodon, the shark which had come so near to making an end of my uncle during our early days on Iriatai!
It was an eerie place. We swam to the far end, and my heart was beating faster than usual when my feet touched bottom and we walked out, side by side, upon the ledge. A glance showed me that the place had been a heathen temple of some sort. Under the hole which admitted light stood a small platform of roughhewn coral blocks, a kind of marae, like others to be found throughout the Polynesian islands. On the platform, with his misshapen back to the ray of afternoon sunlight, squatted a hideous little god of stone, leering and monstrous, with hands folded on his belly and with a grinning mouth. A semicircle of crumbling skulls lay about the idol, and leaning against the rocky wall I saw carved war-clubs, beautifully fashioned spears, and axes of polished stone. Marama touched my arm.
"Let us go," he whispered. "This is an ill place, indeed! I have heard the old men's tales of the days when there were still wild people in the Paumotus; without doubt that tiki is Ruahatu, to whom you heard old Maruia pray. These heads are the heads of men slain here in sacrifice—their bodies were offered to Atua Mao, the shark god. Let us go!"