The silence and the loneliness pressed on my nerves and at that rock I turned to stare back. I could just see Coro-mandel's hull, a dark whale shape bulging from the ceiling of my wet world. The depth meter on my right wrist showed 32 feet. Everything was deadened as the pressure built up on my eardrums. With thumb and forefinger pressed into the hollows of the mask, pinching my nose, I blew my ears clear. Instantly the noise of my breathing, the pops and crackles, the hiss of the demand valve, were preternaturally loud.
Reassured by the dim outline of the boat, I turned and flipper-trudged to the underwater cliffs, gliding weightless along great fissured rocks. Like flying buttresses, Bert had said. But it was the dark, gaping mouths of the fissures that held my gaze. I was thinking of octopuses and groupers big as sharks, my imagination filling the black cavities with all the monsters of the deep.
It was the loneliness, of course. In my two previous dives I had been following Bert. Not only had he been there to instruct me, to give me confidence, but he had kept ahead of me so that I had had him always in my field of vision, a fellow human being who was both nurse and companion. Now I had nobody, and I had to penetrate the deepest of those yawning fissures, negotiate a hanging slab of rock, and then find my way up through flooded caves and blow holes.
I looked at my watch. Four and a half minutes gone already. I should have come in on a bearing, but I had forgotten the diving compass. I wasted time trudging north and had to turn back when I failed to find the fissure Bert had described in such detail. I reached it at 09.58 and hung there, motionless, off the black gut between two buttresses of rock. It was like the entrance to an ancient tomb, or the adit shaft of a drowned mine.
Through my mind flashed the things Bert had told me- the sense of something lurking, his spotlight disappearing, the touch of a body on the surface water of that cavern. Imagination? And then I was thinking of the old man, locked up alone inside those cliffs for more than three days. That was enough in itself to drive a man mad-even a sane man with no knowledge of the prehistory of the place, the world these caves had known before a blasting of the earth's crust had brought the sea flooding in.
Thinking of the old man had one good effect, it overlaid my fear of lurking sea creatures with a deeper, more personal fear. I unhooked the torch from my belt, hung it by its strap to my wrist, and then, with a quick movement of my flippers, plunged head-first into the blackness of the gut. The rock walls closed in, the water skylight above my head a dull, greenish glimmer, but enough to dim the light of my torch.
The depth gauge read 38 feet.
And then the water sky disappeared. I was in black darkness, rock all round and the fallen slab blocking my path. The gap was a long gash barely two feet high, an ugly mouth with sea anemones lurking and the movement of nameless things in crevices and cracks. I could hear my heart pounding, and the hiss of the demand valve, the burp of my bubbles, were loud in the confines, resonant like the movements of some monstrous stomach.
I turned on my side and squirmed my way in, the torch thrust out ahead, my shoulders scraping rock. The cylinder on my back thumped with an unearthly clang. Bubbles of exhalation clouded my vision. Queer sounds dinned in my ears, that stomach coming with me, noiser and more monstrous in the confines.
And then my arm thrust clear, and with a final heave, I was through, back into the vertical narrowness of the fissure, so that I had to flip over onto my belly to still the clanging din of metal scraping rock. The torch showed the walls a paler colour. Limestone by the look of it, which meant that I was already inside the volcanic overlay. Also, they were smooth as glass, a calcareous coating the significance of which I did not appreciate at the time.
More curious than afraid now, I straightened my body into a near-standing position, the tips of my flippers just touching the floor. With my arms stretched up I could touch the roof. It was smooth and curved in an arch. Either it had been fashioned by man, or it had been worn that way by water-the sea or some underground river.
A dozen yards or so farther in the walls fell back abruptly on either side. I had entered the first cavern. Here I did not have to waste time searching for the outlet. I simply breathed in and so lifted myself to the roof, and in a moment I had located the blow hole Bert had talked about.
I switched the torch beam to my watch and was astonished to find it was only 10.04. It had taken me just six minutes to negotiate the entrance. It had seemed an age. The depth gauge read 23 feet.
I was suddenly full of confidence then. The blow hole was more like a rising gallery, but even so it would only be a moment or two before I surfaced in the upper cavern where Bert had seen the rope hanging. And it was in that moment that I nearly drowned. I suppose I had knocked my mask scraping through the fissure. At any rate, there was water in it, and suddenly it was over my nose and I panicked. I forgot that it was my mouth I was breathing through, that the nose didn't matter. Desperate, I held my breath, stationary, alone, only the torch beam stabbing at impenetrable darkness. And then I tried to suck in air through my nostrils, got sea water instead and tore at the mask, driving with my flippers for the surface. But there was no surface, only rock. A rock prison like a huge tombstone holding me in a watery grave. It was the thought that this was a grave that brought me to my senses, made me remember the drill for clearing a mask that Bert had taught me sitting on bright sunlit sand in six feet of water. Lean the head back, hold the top of the mask against the forehead, tilting it, and blow through the nose. I did it, my head hard up against the rock ceiling, emptying my lungs in one despairing snort. Bubbles poured past my face, my head no longer bumping rock as I began to sink; with absolute concentration I forced myself to breathe in through my mouth. The hiss of air as I cracked the demand valve, the feel of life in my lungs again-and miraculously my mask was clear. I felt suddenly drained, utterly exhausted, and yet at the same time wondrously exhilarated as though I had surmounted some great obstacle.
Feeling more confident than at any time during the dive, I relocated the entrance to the blow hole and flippered my way into it, head first. It was circular in shape and about four feet across at the entrance. Inside, it proved very irregular. There were places where it narrowed to little more than a pipe, others where it widened out into expansion chambers, and the angle of the slope, as well as its direction, varied considerably. Also the walls, though smooth, were not glazed like the entrance cave below.
All this was observed more or less automatically, my mind being concentrated on what I would find when I broke surface in the upper cave. Thus it was that, when the beam of my torch showed me a man's legs, I was slow to react.
I had just paused in one of the expansion chambers to glance at my depth gauge. It now read 10 feet and I remember thinking that I was already over halfway up the blow hole. The walls closed in again as I entered a particularly narrow section, and it was then that the beam of the torch showed him swimming away from me.
At least, that was my first thought, seeing in the dim light of my torch the soles of his feet, the white of legs disappearing into the red of swimming trunks. And for a moment I accepted it, noting that, as I checked, he seemed to swim away up the tunnel, his legs trailing off into the miasma of sediment-saturated water through which the torch beam could not penetrate. And because I could swim and breathe in that tunnel it didn't shock me the way it should have done to find another man down there.
I suppose the truth is that my nerves were so concentrated upon what I was doing that my reactions to anything extraneous were uncommonly slow. I went on after him, the tunnel rising more steeply, and round the bend, where it was wider, I saw him lying like a log broadside to me, white shirt clinging to a white body overblown by the optic enlargement of the water.