In the end it was arranged that Van Damm would stay with Holden while Prescott and I, led by the Professor, would press on towards the strengthening light which beckoned in front of us. It took some element of self-sacrifice on the part of Van Damm to suggest remaining behind and I was near to admiring him at that moment. Despite the assumed waspishness between the two of them Scarsdale and Van Damm were close, and they had together hammered out a successful formula for the Great Northern Expedition. It seemed as though Van Damm had cheated himself of the shared glory if we now discovered something even more extraordinary in the growing luminescence of that subterranean place.
Moved by these and other considerations I had myself volunteered to remain behind with Holden, who was now conscious and able to speak. But I was immediately overruled by the two heads of the expedition; apart from being deputy leader Van Damm also had specialist medical knowledge. What could I do if there were some emergency beyond my own sparse rudiments of first-aid? No, said Scarsdale, it would not do; besides, he added sotto voce to me, as we stood alone for a moment, apart from the others, he might have need of my agility and strength at the front.
Prescott was experienced in the use of firearms and would be needed also; so it was arranged. We presently set off, led by the Professor carrying a naked revolver, followed closely behind by Prescott and myself pushing the trolley. In addition to the light machine-gun, ready on its tripod, Scarsdale had also laid out a number of hand grenades within easy reach. I watched these grim preparations with growing disquiet. I did not know what the Professor expected to find but it was obviously something large and inimical to human life if we needed protection on this scale.
We had gone only a few hundred yards beyond the point where we had left our two companions before there was an appreciable strengthening of the light; not only its intensity but its quality. It had a flickering, throbbing property which was hard on the eyes; it seemed to pulsate in time with the vibrating pulse which beat ahead of us with ever-increasing strength.
We could now see our way quite clearly by this illumination; the branching tunnels still led away to left and right but there was no doubt that the one we were following was the correct one; it led, despite slight curvatures to either side, unerringly to the north and both the light and the throbbing pulse which had the strength of a muted kettledrum played at a distance, undoubtedly emanated from this source. I did, in fact, at Scarsdale's suggestion, try one of the branching tributaries to the right but the light faded in a very few seconds and the vibrating rhythm of the pulse-beat with it.
Prescott now drew to my attention some more of the curiously incised hieroglyphs which were carved at various points on the side of the tunnel we were following; I wondered perhaps whether they might be distance marks but the Professor thought not. He puzzled at them for a few minutes and then announced sharply that they were mathematical formulae whose purpose for the moment escaped him. I gave him a long searching glance and by the way he lowered his eyelids I felt that he was not speaking the truth.
The markings appeared to me to be no different to the other inscriptions in the ancient language and I could see no formulae which would make any mathematical symbols. However, I guessed that the Professor had his own reasons for not translating the signs; it may have been that they had a sinister import and that he had no wish to alarm us.
I did, however, persuade him and Prescott to pose for some pictures by one of the plaques and then changed round to allow Prescott to photograph myself with the Professor. As it turned out this was the only picture of the expedition to survive which showed myself. By now we had little or no need of any artificial illumination and could see perhaps a quarter of a mile ahead along the tunnel. It was this factor — and thank God for it — which was instrumental in saving our lives.
A sudden shout from Prescott put my nerves on edge. He was at my elbow, pointing.
'There, man, there. The slime trails!'
I saw what he meant a moment later, before the awful stench was brought to us on the warmth of the strengthening wind. Great, slug-like smears on the surface of the tunnel which led off into unknown debouchments at the side.
Scarsdale nodded as I caught him up. He had obviously already seen them.
'I understood Van Damm saw this back in the square in the city,' I said. 'Why is it we haven't come across them before?'
'Because they didn't want us to see them before,' said the Professor grimly. 'They erased the trails. Now it doesn't matter.'
I had no time to digest this, fortunately, for we were now, as though by instinct, quickening our pace and hurrying on in the ever-increasing white light which continued to radiate from somewhere ahead of us. I put my handkerchief tightly over my nostrils. We crossed the slime trails a moment later; they were awful, more than an inch thick, and our boots skidded on them. I took one look at Prescott's face and it registered the same loathing and disgust I felt on mine.
Then we were through and out on to dry tunnel floor beyond. The great central highway was now rising slightly and curving to the right; the wind blew quite strongly, though still warm, but with a raw, charnel edge to it. The pulse-beat was rising to a crescendo that echoed uncomfortably in the ears. And with it the light level was rising to a vivid intensity. Its pulsations, that echoed the heart-beats in 0ur ears, were becoming uncomfortable to the eye and without waiting for Scarsdale's instructions we each put on our goggles, as at some central order.
At the same moment Scarsdale radioed through to Van Damm and I was reassured to hear the doctor's fluting voice in reply — He had nothing to report and Holden appeared to be gaining strength. He thought he might be fit to move within an hour or two. Scarsdale in signing off, said he would leave the radio-link open from now on. Prescott and I were finding the trolley a little heavier with the steepness of the slope and Scarsdale put his great shoulder to it, which helped considerably. So we tottered onwards up the steeply increasing gradient to where the blinding light mingled with the drum-beat of the unknown pulse.
My ear-drums were almost bursting and my sight glazed with the pulsating light as we gained the top of the slope. We all three let go of the trolley and staggered like drunken men to where something like a gigantic door opened and closed to the drum-beat. Even with the goggles the glare was so intense that I had to close my eyes to mere slits. I slumped to the floor of the cave and with Scarsdale and Prescott at my side forced myself to gaze at that stupefying vision.
The light was so white and incandescent it seemed to come from some realm beyond the stars while it was so bound up with the pulsations that it almost burst the brain. I turned to Scarsdale. His face was like a vivid etching in the white heat which bathed all of the scene before us. Apart from the rock floor which stretched away from us there was nothing else visible in the world but the palely writhing light-source which might well have led to eternity.
'The Great White Space!' said Scarsdale, his hand tightening on my arm, his face aglow with knowledge. His thoughts were etched as almost visible manifestations on the pale fire which writhed on his countenance. He shouted above the roaring rumble which mingled with the pulse-beat like a gigantic furnace.
'The Door to the Universe. The Door through which the Great Old Ones pass and re-pass.'
I did not profess to understand what he was saying and presumed merely that he was naturally overcome by the vastness and unexpectedness of the vision. I heard Prescott I cry out then and turning, saw that his face bore an expression of loathing and horror. Scarsdale had just commenced a transmission to Van Damm but he stopped in mid-sentence. A loathsome putrescence had begun to manifest itself within the tunnel. It emanated out there somewhere beyond the veil of blinding light which shone before us like a million suns.
Then I saw what Prescott had already observed and almost lost my sanity. How shall I explain or describe the nodding horror which edged its way from the pale luminosity into our view? It was a colossal height which accounted for the vast doors through which we had ourselves passed on our way to this abode of abomination. The thing made a squelching, slopping noise as it progressed in a series of hopping jerks and with the noise came the stench, borne to our nostrils by the warmly acrid wind which blew as out of the vastness of primeval space.
The very brightness of the light which surrounded it with a white-hot glow mercifully prevented too close a view. The head of the thing, which appeared to change shape as it hopped along, was something like a gigantic snail or slug, while vague, lobster-like claws depended from its middle. In general form it appeared to be monadelphous; that is, a number of filament-like particles made up what we should call a body, uniting into one bundle from which depended the claw-members.
Worse still, other similar forms appeared from behind it, like an army of half-blind beings, surging in from the glowing air like subterranean creatures from the depths of the sea. But most unnerving of all was the noise which emanated from them. From a lowing bellow like cattle at the bass end of the scale to the high shrill mewing of a cat at the other. Can anyone blame us if we all three, seized by some primeval impulse, manhandled the trolley, backed swiftly with it and — I am not ashamed to say it, even of the great Professor Clark Ashton Scarsdale — ran for our lives?