Yet we three were quite content to follow, each using his own specialised skills none of us really knowing anything of the big questions that were taxing the complex minds of Scarsdale and Van Damm. I knew that they would, of course, tell us everything when they were ready but it argued a high degree of trust on the part of such highly qualified specialists as Holden and Prescott. With these and other such thoughts I passed an hour after coming off the midnight duty and my last vision was of Van Damm polishing his glasses in the cheerful aura of the lamp before sleep found me.
We were breakfasted and packed by six the next morning and on the move shortly after. There had been nothing to report during the night from any of the sentries but despite this Scarsdale insisted that Holden and Prescott, who were wheeling the trolley on tnis occasion, should mount the machine-gun on its tripod, ready for instant use. He also ordered that each of us should carry a Very pistol in addition to side arms. This was not only for signalling purposes — after all we had the radio link for that — but to illuminate anything which we wanted to investigate. We had already tried firing the pistols some days earlier to see if they would reveal the height and extent of the roofs of the gigantic cave system. While spectacularly illuminating the cloudy distances, they had been remarkably unsuccessful for that purpose.
Fired at the 'sky' they curved upwards for hundreds of feet and on exploding burned as a faint glow beneath the layers of misty vapour which hid the roof from us and which gave the illusion of the sky. But as they came closer to the ground they gave a brilliant and blinding light compared to the low intensity illumination we had been used to. To detect ground targets they would be incomparably useful. I for one, though secretly grumbling at the bulkiness and weight of the pistol I was forced to carry, later came to realise their usefulness in our situation and on at least one occasion the Very lights saved my life.
Soon after we started the day's march the tunnel became narrower — it was now down to about thirty feet wide and then started splitting up into branching tunnels and diversions; when we first came upon a tributary, something most unusual in our exploration so far, Scarsdale dealt with the matter quite simply. He chose the largest tunnel which still pointed to the north and down which the warm wind blew. There was a purpose behind the master tunnel as Van Damm called it and this remained the principle of selection throughout.
Scarsdale had also organised elaborate precautions for finding our way back from the labyrinth in which we were now picking our way. In addition to simple chalked arrows on walls and the tunnel floor, which reminded me of childhood games, small metal discs were fastened by suction pads at particularly difficult and elaborate junctions. These were miniature beacons which Holden and Prescott had developed and the radio equipment we carried could be tuned in to them to guide us back.
'Unless anything realises their purpose and removes them while we are gone,' said Van Damm grimly. I was impressed by the fact that he did not say 'anyone' and it was a thought which did not bear dwelling on. I queried in my mind yet again whether in fact the strange creature Holden had spotted was responsible for the unique and horrible manner in which the dwarf Zalor had met his end. And leading on from that, whether such creatures — I could not imagine that one only would be unique in such a vast underground complex and presupposed there must be others — had something to do with the people who had carried out the ancient embalming processes on the weird insect-like beings in the jars.
We walked slightly uphill for an hour without seeing or hearing anything untoward; the pulsations were becoming much clearer now and seemed to vibrate the very ground over which we advanced. Unmistakably also, and this represented a fantastic change in our conditions, it was becoming lighter. Van Damm was the first person to notice this I believe, though typically he kept it to himself for almost half an hour until he was absolutely certain. And indeed the process was so subtle and delicate that the floor, walls and the distant vista along the corridor we were traversing etched itself fraction by fraction on our retinas, so imperceptible that it took minutes to realise that the scene around us was 'developing' itself, much as a photographic plate creates an image in the photographer's dish.
I saw Holden's face change to a mask of wonder in the rapidly strengthening light; it was like being reborn after months in semi-darkness though in reality I supposed we had been underground for something like a fortnight. But here a day could seem like a month with the feeble glow of the artificial sky and the shifting patterns forming in the wispy afterglow which served for atmosphere in this place.
Scarsdale and Van Damm exchanged triumphant glances and I realised that this was what they had been expecting all along; that the central premise of the whole expedition, probably known only to them, was at last coming to life before their eyes, transformed from dusty parchment and well-thumbed typescript and page after page of abstruse calculations.
'The Trone-Tables were right, Professor,' Van Damm muttered, his thin savant's face alight with strange dreams. 'Allow me to congratulate you, sir.'
And impulsively, he moved forward, and began to pump Scarsdale's hand.
The big man blinked slowly in the strengthening paleness that glowed along the walls of the corridor, obviously moved. I stepped to one side, leaving them to their moment of quiet victory. The others sensed that something important was about to happen and as if by a common impulse withdrew to a discreet distance.
Van Damm and the Professor stood together for the next ten minutes, consulting their notebooks and tables of crabbed notes before rejoining us.
'All will be made clear to you, gentlemen, very soon,' said Scarsdale crisply. 'You have all been patient and extremely forbearing, I must say. I calculate — and I am sure my colleague here will confirm — that we are nearing our objective; the end of our epic journey and one that will, I am sure, be destined to go down in the epoch-making explorations of this first half of the twentieth century. I say this without self-importance or undue pomposity and without taking the credit to myself. I could have done nothing without the unstinted efforts of each of you and 1 would-like to thank you here and now for everything that you have done and will do before we bring the task to a successful conclusion.'
It had been a long speech for the Professor and he had evidently been moved; he paused for a moment, his face flushed and the light shining on his strong features etching his beard with shadow so that he looked more than ever like an engraving of some age-old god or perhaps a Viking raider from the North.
'An honour and a pleasure, my dear Scarsdale,' said Van Damm awkwardly, on behalf of us all.
'Well then,' said Scarsdale, with a return to his old manner. 'We press on. But first a commonsense precaution.'
He crossed over to the trolley and grunted as he rummaged about among its contents. Presently he opened a sealed package of canvas. He handed its contents round among us. I found myself clutching a pair of deeply tinted snow goggles with heavy elasticised straps.
'A curious item, perhap's,' said the Professor. 'You possibly wondered why these were shipped. You're about to find out. I have many theories but I don't know how strong this light will get.'
There was a perceptible stirring among the party at this and Prescott queried, 'Do you mean to say that we are approaching the open air?'
Scarsdale shook his head.
'This light comes from a subterranean source of whose origins I am not certain. There may be some danger without the goggles. I would like everyone to put them on when I give the order. And not to remove them under pain of the most serious consequences.'