The remainder of that day was spent in a fevered chaos by Scarsdale and Van Damm in particular. Though the discovery of the picture-machine in the ancient city beneath the ground was of stupefying importance from an archaeological and historical point of view it did not excite me as much as might have been supposed. Naively, I had imagined that we were to see something like early newsreel films of this long-forgotten civilisation. Instead, the reality, when it came was much more prosaic though the Professor and his scientific companions passed an evening much like that of Lord Carnarvon and Howard Carter when they discovered the tomb of Tutankhamen.
In point of fact what the Great Northern Expedition had unearthed was equally as important, possibly more so, as the city of Croth had never even been suspected until Scarsdale and one or two obscure scholars had begun their researches into certain forbidden books. What Scarsdale and Van Damm had reanimated in what they came to call the Central Library of the city was, in fact, a visual method of projecting book pages so that hundreds of people could take part in readings at one time. This would not only have served the same function as our modern cinema for this ancient people but obviously took the place of printing for them, as by this method they had only to 'publish' one particular book for the entire population.
When Van Damm himself discovered the central deposits, the raison d'etre for the whole building, there was a high pitch of excitement so that I felt constrained to go back across the square to relieve Prescott, so that he could join in an occasion of outstanding interest. What the doctor and Scarsdale were so enthused about was, I had to admit to myself, something pretty spectacular in the way of breaking new ground and the Great Northern Expedition would go down in history for this alone.
What had happened was that Van Damm had accidentally dislodged a bronze knob somewhere behind the lectern; the others had felt a draught shortly after and had then noticed that a dark slot had appeared' in the rear wall of the building. The lever apparently operated an ingenious series of counterbalances, sliding back a stone door cut from one slab of material but so thinly and accurately that my colleagues found it could be pushed to and fro with one hand.
What they found within, ranged upon minutely indexed stone shelves and in elaborately inscribed storage bins, were thousands of exquisitely engraved metal cylinders. How these had been created, it was not clear, as there were no tools discernible, but no doubt, Scarsdale surmised, we would find metalworkers' shops and those of other skilled artisans within the city itself.
The cylinders contained many different 'frames' of material, each evidently representing a numbered page of a book or communication. The figures and symbols were punched with such delicacy and precision — letters like O having the central portion linked to the main symbol with exquisitely fine tracery work — that they could be projected complete to give a representation of the page upon the stone screen in the auditorium below.
When the cylinders were placed on a central pin on the machine, which presumably had some sort of light source within its hollowed-out interior, it could then be revolved to bring various faces of the work projected to the viewer's notice in proper numbered sequence. Van Damm himself had expected there to be a series of lenses, as in a modern movie projector, but this proved not to be the case.
The light, whose source remained a mystery, passed through a sort of pinhole as in that old form of camera, and by a racking device which animated the spindle, could be focused by natural light intensity, funnelling it through the metal ring on the exterior of the pulpit. We then realised that the design of the mechanism, which could only 'focus' within very narrow limits, made necessary for the whole building to be constructed to suit the apparatus. In other words, the length of the projector's 'throw' determined the point at which the rear wall screen would be built. The effect can be realised by noting the projection of a sign on a glass door when sunlight repeats the pattern on a light wall some distance away.
There was no denying the tremendous nature of this discovery, and Scarsdale and those who followed would be able to learn much of this ancient civilisation from the deciphering of the cylinders. But further examination would have to wait as we had the whole city before us, wide open for exploration. I took the first watch as sentry that night and noted that the sleep of my companions was markedly broken by the excitement of this extraordinary day.
The following morning Holden was left in charge of Camp Five, the inevitable machine-gun pointing its snout along the plaza in the northward direction to which we were committed. Scarsdale had decreed that for the moment we would explore only those buildings of greatest importance which lay directly on our route. It was his aim, he said, to penetrate as far to the north as possible -1 myself believed he intended to seek out the source of the strange distant throbbing — and only to explore the city in depth upon our homeward journey.
It was about ten a.m. when the party left, Scarsdale and Van Damm leading, as always, and myslf, as the least scientifically useful member of the expedition in the rear. The expendable position Prescott called it jocularly, and though we all laughed, it was a somewhat macabre joke to my mind. But perhaps Prescott was a more effective psychologist than he realised as his words served to sharpen my wits so that I kept a more than usually alert watch from my vulnerable rearward position.
The northward-leading thoroughfare, which nevertheless had a disturbing optically-distorted quality about it, led away through what in a normal city would be described as the suburbs. The size of the buildings diminished as we left the square, though they were still upon an impressive scale. The light, to which we had now become accustomed, was of the same overall strength so that we did not need any artificial aids to illuminate our way. The distant throbbing was growing more distinct as we tramped onwards for more than an hour; the structures here, into which we occasionally ventured, were nothing more than empty square boxes with no windows but merely steps upwards, a portico and a square door punched in the surface.
The material was the same steel-hard stone that we had already observed. Before we left the square proper we also ventured into one or two other large buildings but despite the inscriptions on the lintels we could not make out their purpose; one appeared to be a sort of office, with large square flat slabs of stone which might have served as counters. There were no chairs or furniture of any other kind. The floors were of the same smooth, interlocking stones which gave the aberrant optical effects I had already noted and were free of dust or detritus of any kind.
The second building seemed to be some sort of warehouse, full of jars and square vessels all sealed and there were also piles of thin stone slabs which bore incised writing in a language different to the hieroglyphs, Scarsdale said. We did not open any of the sealed jars or boxes, in view of our previous experiences in the embalming gallery. The roadway led slightly uphill, always due north, and with other roads, built on a smaller scale running at exact mathematical radii from it; almost always at rightangles. Just before noon we came to a sensational innovation, a strange, four-arched bridge, that seemed to be suspended from either side of a large stream about forty feet wide, but of some unknown engineering principle as the bottoms of the arches nowhere appeared to touch the water.
This caused a great deal of excited speculation between Scarsdale, Van Damm and Prescott and it was quite some while before any of us ventured on it, as it seemed so frail. It proved to be of some unfamiliar metal and even more bizarre, nowhere was there any evidence of nuts, bolts, rivets or welding as known in the modern world.
Scarsdale summed it up well when he turned to me and said, 'If I didn't know the thing was impossible I would say that this whole structure was carved from one block of metal by some gigantic force.'
Van Damm's face was white as he gazed around him in the gloom.
'Just why do you say it is impossible, Professor?' he said quietly. 'I should say this is one word which it would be unwise to use down here, judging by what we've already seen.'
It was the only time I had seen Scarsdale at a loss for words. He coughed awkwardly and shifted his huge feet in the riding boots.
'Perhaps you're right. Van Damm,' he said mildly. 'One cannot always judge properly without all the relevant data. I should perhaps have qualified my remarks.'
Van Damm said nothing in reply but went to the smoothly burnished balcony of the bridge, which ran in a shining, slightly curved arc to the further shore. He gazed down into the turgid, rippling water, which gave off a slight luminescence. There was a current here and it ran back in the direction from which we had come. I ventured to say that this river probably drained into the lake which we had crossed and was gratified to learn that the leaders of the party were already of the same opinion.
Nothing showed on the surface of the river; there appeared to be no life in the depths; and no flotsam or any other debris was carried down. At least, not while we were there and we lingered for an hour in that strange spot.
At last we moved on, reaching the far shore without incident. I looked back towards the city but it was already lost in the haze. I could not help reflecting, with a sinking of the heart, that we were committing ourselves more and more into the interior of this bizarre and terrible place, with every day that passed; if anything malignant were encountered it would be very difficult, if not impossible to fight the long miles back.
We lunched on the opposite bank of the stream, where there were no buildings or vegetation of any kind, just the bare unyielding rock and sandy particles of grit to which we had long become used. Scarsdale had decided by this time that we would continue in the northwards direction together and to do this it was necessary that Holden rejoin us. I contacted him by radio — we had been in touch at intervals all the morning — and Van Damm said that he would go back. The two men would then load the machine-gun and heavy equipment on the trolley and rejoin us in the afternoon.
Van Damm had been gone several minutes and had in fact disappeared in the haze across the bridge only a short while before when there came a sudden stammer from the machine- ' gun which reverberated and echoed in the most awful way across the miles of caverns. There were separate and distinct bursts but the muted thunder of the explosions was constantly repeated under the cave roof and created such a menacing effect that our party instinctively cowered away as though we ourselves were under fire.
The noise was so unexpected and so shocking that none of us could at first think what it meant; that Holden had fired at something was obvious but this underground atmosphere was so arid and lifeless that it was difficult to think of a possible target.
I found Prescott at my side; his suggestion was that of a signal but Scarsdale immediately ruled that out as Holden had only to use his radio. We expected Van Damm would immediately hurry on to Holden's assistance and indeed he came through on his handset almost at once. I then tried to reach Holden on the radio link but with no success.
'Keep trying,' Scarsdale told me, almost savagely. His bearded face looked more like a Viking than ever as he gazed about him, his revolver cocked and ready for use. I remembered then the fate of the dwarf Zalor and realised what had never been absent from our leader's mind; that this underground world harboured many ancient and evil things which would only reveal themselves when they were ready.
'Has Holden been attacked, do you think?' Prescott asked the Professor.
Scarsdale shook his head impatiently. 'We shall know in good time,' he said crisply. 'I blame myself for splitting the party. Holden was possibly the wrong person to leave on his own like this. His nerves have been uneven ever since we found the dwarf”s body.'
I looked at him in surprise as it was the first time he had ever directly mentioned the incident.
I shall never forget the long hour we sat by the bridge parapet, looking across the stygian water and listening to the incessant crackle of the radio set; my own nerves were stretched high and I expected minute by minute to hear another shattering series of explosions from the machine-gun. But nothing came and my tension eventually died away.
Then, at about two o'clock in the afternoon to our intense relief we heard Holden's voice on the radio. He apologised for what he knew must have been a startling incident. He had fired, he said, at something which was moving towards him between the buildings at the edge of the plaza. He had then gone off to investigate, leaving the radio, and had only just returned.
Scarsdale moved to take the microphone from me at this point. I forget his exact words but his clipped tones and reproving, if urbane, remarks had the desired effect; Holden did not afterwards forget the Professor's strict instructions.
'Well,' he said at length. 'There appears to be no harm done and I think you can take it that anything down here would be alien to human life as we know it. We will not come back but I'll await your report when you return with the doctor.'
Scarsdale instructed Holden to dismantle the equipment; he and Van Damm could then investigate the area further on their way to re-join us. He would keep the radio link open constantly from now on. A few minutes later Van Damm's tetchy voice came through. When the two men came across the bridge pushing the trolley full of heavy equipment later in the afternoon, Holden told his story in person to Scarsdale as we all crowded round. He had been sitting in the square making notes, he said, when he became aware of some faint shadowy thing which appeared to flit between the far buildings at the end of the plaza.
The occurrence was so unusual that he kept watch on the one point for several minutes; he had thought that it was the optical illusion which we had found common to the city but he soon realised that a large 'hopping thing' as he described it, was moving about between the block-like structures at the edge of the square and gradually coming closer. Not surprisingly, he did not like this, and rapidly got behind the machine-gun.
After another quarter of an hour passed, the thing, which appeared to be grey in hue and of enormous size, stood still; Holden got the uncomfortable impression that he himself was being studied and he reached for his binoculars. He had difficulty in focusing the glasses but as soon as the thing began to come into reasonably clear view, its aspect was so disturbing that Holden became greatly agitated and was unable to hold the binoculars properly. It was only a few seconds after that before he let off a burst with the machine- gun, followed by two others, as the thing made off into the distance.
Courageously, under the circumstances, but foolishly as it now appeared, Holden then set off with one of the elephant rifles to see whether he had wounded the creature. The satisfying noise of the machine-gun had given him back his courage and he hoped to find whether he had hit it. He did find one or two of the flattened bullets from the gun lying at the edge of the square but so far as he could see, there was no sign of the creature and of course the buildings themselves were of too hard a material for the impact of the bullets to make any impression on them.
It was only after he had reported to us on the radio and Van Damm had reached him that they had seen any other evidence of the creature. He and Van Damm had taken a slightly different route out of the city, in order to pass by the spot where the hopping thing had been seen.
'There was a trail of slime leading off the edge of the square,' said Van Damm grimly. 'The stench was awful and we didn't follow it up.'