I lingered for a moment, looking for a lens-cap which had somehow escaped its cord and fallen to the ground. As I found it and replaced it on the camera I was startled to hear again something I had heard before, echoing from the darkness beyond the lintel of the great door. It sounded like the distant beating of gigantic leathery wings.
Curiously enough, that evening saw a reversal of our usual practice regarding the camp sites. It may perhaps have been the brooding atmosphere of the great entrance in front of the mountain; or possibly the connotations of the message on the massive stone obelisk but without anyone saying anything specific those of us who were driving the tractors formed them into the familiar triangular pattern on the sand outside, well before darkness fell.
Neither was there the usual camp-fire gathering. Instead, we all foregathered in Scarsdale's Command tractor for a rather special meal. Holden, who was acting as cook on this occasion, excelled himself in preparing the tinned delicacies and Scarsdale himself even went so far as to break out three bottles of champagne from our precious reserve store.
He did another strange thing also; there were, in the roofs of the tractors, special skylights of toughened glass, which were protected inside and out by heavy steel shutters, controlled electrically. I had never seen these in use during training in Surrey or in the field, but tonight, moved by some whim, the Professor drew back the shutters. The brilliance of the stars overhead illuminated the interior of the vehicle and Van Damm moved to the control panel, clicking switch after switch, until all the interior lights were off.
The faint luminosity from outside grew in strength until it seemed to us as though the starlight were bright enough to read by; we must have made a strange sight, sitting in that pale glow, sipping champagne, the only other sources of light the minute radiance given off by the Professor's pipe and by the tip of Van Damm's celebratory cigar.
Then, after half an hour of this, Scarsdale got up to trip the light switches and the shutters rumbled back across the skylight. The atmosphere grew brisker. The Professor gave us a final briefing; he urged caution on the morrow and reiterated his instructions on the importance of the radio link. He reminded us too that we should be using the searchlights on the tractors under field conditions for the first time.
He himself had charted the way on his previous journey and he anticipated no difficulties during the first day; we would wear light clothing as the caves and passages were warm and dry. We would carry sidearms at all times and no-one was to leave a vehicle without specific permission from him as leader of the expedition. All this was sensible enough and yet I felt a faint unease as he continued his discourse, his strong face outlined in the glow from the Command vehicle's instrument panel. I thought again of the leathery flapping I fancied I had twice heard from within the cave entrance. I
wondered, not for the first time, what were the Professor's reasons for taking along so many heavy weapons. Looking round at the racks of equipment and lethal arms in the interior of the tractor, I reflected that we seemed more like a band of mercenaries invading a fairly weak nation, than scientists bound on an archaeological field expedition. It was a feeling which persisted long after the start of our journey the following day.
I slept badly this last night. I drifted off to sleep on each occasion, only to awake an hour or so later, my mind vaguely troubled. The last time I looked at the illuminated dial of my watch to discover that it was only a quarter to four in the morning. A sudden scraping noise jarred my nerves; the bright yellow of Scarsdale's match threw a glow over the whole interior of the tractor. He puffed irritably at his pipe for a moment or two, his strong features beneath the beard looking like the image of some old Nordic god. It was a comforting sight before it died, leaving only the faint glow of burning tobacco.
I heard the rustle of blankets as Scarsdale put his matchbox down somewhere on his bedding.
'Are you awake, Plowright?'
It was a statement not a question.
I admitted that I was.
'You are worried about the coming operations?'
The word had slipped out; once more the activities of the expedition had assumed those of a military adventure, rather than that of a strictly scientific affair.
'Only inasmuch as your true purposes are obscure to me. Professor,' I said. 'I have every confidence in your abilities both as a man and as a scientist, if that has any value to you.'
'Thank you, Plowright,' said Scarsdale. 'It is true that I have been perhaps a little lax in not preparing you more fully for what we may find. But that is only because I myself am not certain. Most of my reasons exist as mere theories in my notebooks. I would prefer to measure them against actual experience in the field.'
'I quite understand,' I said. 'Please do not think I am complaining.'
I found myself searching for the right words. The Professor said nothing but emboldened by the steady and comforting glow of his pipe in the darkness, I went on.
'I must admit the size of that doorway and the somewhat forbidding inscription on the stone had a certain effect on my mind,' I told him. 'But you'll not find me wanting if we run into any difficulties on this trip.'
'I never doubted it, my dear Plowright,' the Professor said. 'That was one of the major reasons for your selection. But you have other reservations? Your tone seemed to imply it.'
'They're perhaps too intangible to qualify,' I said hesitantly.
'Would you care to trust them to plain speech?' the Professor said, with a return to something of the manner he had maintained when we were training in Surrey.
'Fancies, perhaps,' I said. 'I am possibly over-imaginative where such places as this are involved. Your models, the caves and the other details you gave us in the original briefing were among my major reasons for coming along. Imagination's my strong suit, as you may well know and I certainly need it for my photography and artistic work.'
'And you felt the Great Northern Expedition would give you such scope in your capacity as cinematographer and official cameraman?' he concluded for me.
'Something like that,' I admitted.
The Professor was silent for a long moment and then I heard the soft click as he put the dashboard panel lights on; their blue dimness outlined the details of the cabin.
'But you now feel that your imagination may be a handicap once we get underground?' he continued.
'It may be,' I said. 'Though we shall be within the tractors most of the time. I have been underground before, of course, but it's not just that. There's something different about this trip and not only from what you've said, though that was bizarre enough.'
'Would you care to give me a concrete example?' he asked.
I hesitated for another long moment. Then I told him about my feeling at the entrance of the cave.
'Ah, then you heard it too,' he said sharply. 'I wondered at the time. Yes, it was very like the beating of wings, as you say. Bats, perhaps.'
We did not return to the matter again and in a few moments more we slept. But within I did not think the noise I had heard had been made by bats and I could swear that the Professor did not think so either.
Nine
The honour of being the first one within the great portal was given to Holden; I say honour, such as it was, because the event, like most long-awaited incidents, was almost an anticlimax. We were awake and out early next morning and soon after six a.m. the three tractors affronted the morning air with their motors. What little sun there was penetrated our dank spit of dark sand reluctantly and its gilt was soon lost again against the black, basaltic rock which seemed to absorb light and somehow stain it. The simile is fanciful, I know, but the only one that readily springs to mind.