The first thing we noticed was that the sluggish tide which rose and fell a foot or two on the shallow shelving shore, was itself as phosphorescent as the light which came from the sky. In between was a sort of vaporous mist which hung in thin sheets over the surface of the water, so that we were able only to see about two hundred yards out from the beach, when all was lost amid the indistinct haze. But the faint luminosity of the water, the brief lacunae caused by the mist and the recurrence of the vibrating brightness from the vast roof of the cave, hidden from us, made the whole atmosphere nothing more reminiscent than some great painting of Turner, gigantically enlarged.
We walked for about a mile westwards along the beach until our passage was barred by a configuration of rocks which thrust out into the water, so sealing us off, as the landward side of the mass was sheer and unclimbable. We came back, each heavy with his own thoughts, all of us exhilarated and moved at the strangeness of our surroundings. On our return I relieved Prescott who was then free to join the others in another sweep to eastward. I remained on top of the tractor, straining my eyes until the last of my companions had dissolved into the blur of the atmosphere.
I passed a long hour and was then relieved to see the four of them returning. They had found a similar situation to that obtaining to the west. A broad beach, misty water and finally impassable rocks. Scarsdale was inclined to the theory that the rock formations were masses broken away from the main walls of the vast cavern when it had solidified in pre-historic times and the others were of similar opinion. None of them felt that the rocks had any particular significance and that if it had been possible to scale them they would have merely led the explorer, sooner or later, to the blank, impassable walls of the main cave.
From figures the Professor had worked out, based on measurements and theories expounded on his walk, he.had advanced the opinion that the lake or tarn, despite its apparent tidal tendencies, would not prove to be of vast size, though he had surmised it might be a mile or more in width. We were not proposing to explore — its longitudinal limits and Van Damm felt that the tide might be caused by inlets, at some vast distance beneath the earth, running down into one end of the lake and out at the other.
We debated earnestly within the tractor that evening and many were the theories that Van Damm and Scarsdale argued; it was, from my point of view, one of the most stimulating and interesting evenings we had yet spent, the burden of the earlier nights having given way to a light-hearted optimism on the part of the three junior members. Even Holden was more like his normal self, though I noticed, that, even when off watch, he cast occasional glances through the windscreen, as if to assure himself that all was well outside.
Van Damm had taken the first of the two-hour watches and was, thus, the first to observe the sheer monotony of the atmosphere here, the light never varying by the slightest degree from the overall twilight. But even this mundane fact was written up in the voluminous notebooks which the Professor and his companions were beginning to fill with columns of figures and other statistics. I took my own watch at four in the morning and though the slight breeze from the north still blew, the atmosphere was not damp as might have been supposed from the nearby presence of water; neither did I hear or see anything untoward.
Ever since the strange flapping noise I had first heard at the great portico entrance several days ago, which might now almost be measured in years so long did we seem to have been beneath the surface, my nerves had been playing me strange tricks. The horrifying and quite unexplainable death of Zalor had completed the stealthy undermining of my morale and so I faced my first turn of sentry-duty, my companions all being asleep, with rather more tension that I would have liked.
But all passed without incident as did the subsequent spells of watching over the next two days. We fired the various weapons, with differing degrees of success, the dull explosions seeming to start weird echoes from far off across the water. We hauled the rubber boats down to the edge of the brackish lake and embarked, paddling a few hundred yards out into the mist by compass, and then turning again, making our way back to the beach without mishap. The rubber lifebelts were duly inflated and each of us — not without forebodings, though the water had been already declared non-injurious to health — plunged into the cold tide until their buoyancy had been duly tested.
These, and other equally strenuous enterprises occupied us for the allotted time, until Scarsdale had professed himself satisfied with our efficiency. On the third morning, after a substantial breakfast, shortly after seven a.m. the five of us, in two rubber boats attached one to the other by the painters, slipped into the cold tide, leaving the two locked tractors shrouded under their tarpaulins, and splashed out somewhat hesitantly into the misty unknown.
Twelve
Scarsdale, Van Damm and Holden embarked in the first rubber boat, while Prescott and I followed. The noise of the paddles, the dripping of water, seemingly magnified by the mist and the curious pallor of the light from above made an unforgettable scene as we thrust out from the shore and were soon undulating on the choppy surface, our horizons limited by the faint mist which clung to the surface.
The rubber boats were dangerously low, we had packed so much equipment in with us and I hoped that the current would not get any stronger farther out; if we had to paddle for our lives Prescott and I were singularly ill-equipped for the task. Scarsdale's boat carried the compass and we were attached by the rope in any case so we had no navigation to do. Even so, we were hard put to it to keep up and every so often Scarsdale's sharp injunction would come across to us as the line went taut, due to our inability to match their speed.
But after half an hour Prescott and I had settled down to stroke and our thoughts wandered in a pleasant form of euphoria, our responsibilities surrendered to those on the main craft, our minds as well at ease in this place as they would ever be. We needed both hands for the paddles, but even so our rifles were hardly at our feet, wedged against crates, cases and bundles of camping equipment. My main concern had been the safety of my cameras and my supply of photographic plates; to this end I had secured them in the middle of the mound, well wrapped in waterproof material. My companions had regarded my possibly excessive precautions as faintly ludicrous and even Van Damm was tempted to remark, on embarkation, 'We aren't going to America, Plowright.'
'Who knows where we are going?' Scarsdale had put in unexpectedly and, on reflection, he was, of course, right. The lake might be of enormous extent, if it were on the scale of the works we had already seen. My reflections were interrupted at this point by a sudden lurching movement of the craft, and its tipping at one end, accompanied by a slight ingress of water. My smothered exclamation was followed by a curt shout from the Professor and a muttered apology from Prescott, who had caught his paddle in the securing line.
The interruption was timely, however, and I looked more sharply about me, noting that the phosphorescence of the water remained unabated; that the slight tidal movement continued; and that the surface vapour had receded a little so that our two craft floated in a clear circular area about half a mile in extent. The illumination from above continued steadily so that we seemed to be sailing beneath the dim sky of earth and the warm breeze which had blown steadily from the north appeared, to my imagination at least, to be a little stronger.
With it, I fancied a faint vibration as of some great machine a long way off, giving out a pulsation like a heart-beat. I glanced at Prescott but saw that he had already heard it and looking ahead, I could see that the other party had stopped their vigorous paddling and were all poised, water running off their paddle blades in fiery particles, as they listened intently.