Then his pickaxe suddenly slipped into an empty space beyond the wall. Before Artem had time to realize what had happened, grayish smoke began billowing from the hole with a whistling, hissing sound, covering the handle in a moment.
“Hold it!” Ivan Semenovich cried out, alarmed.
A jet of gray smoke shot from the small opening made by Artem’s last stroke. It was coming out under great pressure like water from a fire hose, sizzling and spreading in the air, sinking slowly to the ground. It flowed down in waves, burying the feet of the four people.
The alarmed dog began barking furiously. She jumped onto a broken stalagmite with a flat top and standing there, went on barking resentfully at the spurting smoke.
“What kind of gas is it?” asked Lida in a half-puzzled half-frightened voice, stirring the thick gray waves at her feet with the pickaxe.
Nobody knew the answer. It was definitely not mine gas since it had not exploded or caught fire when it came in touch with the flames of their miner’s lamps. Besides, the limestone environment was not conducive to the natural production of the mine gas. The archeologist, greatly intrigued, together with the rest, watched the gas flow down the slope like some viscous liquid. Then he stopped over and scooped a handful of the strange gas. It swayed in an elipsoid cloud in his palm without dissolving into the air or even dissipating. A very strange phenomenon indeed. Dmitro Borisovich sniffed the gas.
“It doesn’t smell of anything. But…”
He buried his nose into the gas.
“But you can’t breathe it. It lacks some vital ingredient, most probably oxygen.”
Artem inhaled some of the gas too but failed to discover either a taste or a smell in it. Something viscous and deadly heavy had lodged in his chest after he had breathed it in. An extremely unpleasant thing, this gas.
“Oh, look!” Lida cried out.
The gas was slowly filling the cave, its level rising exactly the way as if it were water pouring in. The gray waves of the gas undulated very close to the clear white flames of the lamps. Then one of the flames sputtered and;went out! The acetylene began spurting from the lamp with a characteristic sound, spreading its unpleasant sweetish smell around.
“The gas seems to be carbonic acid. It does not burn, neither does it allow anything else to burn. And you can’t breath it, since it has no oxygen,” Ivan Semenovich said, thinking aloud. “Artem, turn the gas regulator on the lamp down to cut off the flow of the acetylene.”
Noise of something breaking loose came from the walclass="underline" a huge piece of earth had been dislodged under the pressure of the gas and fell down with a crash. Now the gas began spurting like a big fountain, describing a wide arc in the air and falling down to flow into the cave in seething waves.
“We must retreat, my friends! The level of the gas is rising, and we can’t breath it. It’s dangerous to remain here any longer,” Ivan Semenovich said and then stopped short, going pale. Where could they retreat? To get out, they would have to go downward, retracing the route they had taken to reach the wall — a route which began on high ground but sank quite considerably to form a depression and rose again only a short distance from the rockfall. So down in the hollow, the gas would be the thickest as it was naturally flowing downwards. There was no way they could return the way they had come. In other words, there was nowhere to retreat! And the level of the gas kept rising; it was already up to their knees. What was to be done?
As far as they could see in the dim light of the remaining lamps, the waves of the dreadful gas were surging all around them; the level was rising implacably. It was impossible to.stop up the opening, for it had become wider under the pressure of the gas.
Ivan Semenovich looked around: Dmitro Borisovich appeared calm, his anxiety betrayed only by his tightly pursed lips; Lida was leaning against a stalagmite in a halfswoon; Artem was standing at her side. The young man’s big eyes moved back and forth from Lida to Ivan Semenovich anxiously, as though seeking advice, waiting for an order from the geologist that he would carry out immediately. The dog kept on barking furiously at the dense gas that was flowing ever closer to her.
“Climb on top of the broken stalagmites! The flow of the gas will probably decrease!” Ivan Semenovich called out. “The quantity of gas beyond that wall cannot be unlimited! Quick!”
It was the only thing left to do now — to move higher and higher, away from the dreaded waves of gas! Maybe it would all settle in the lowest part of the cave… But Ivan Semenovich realized now that this was a futile hope. To see it, all one had to do was to look around. The gas was pouring in much faster than it was settling in the bottom of the cave; its level was continuously rising. The bases of the stalagmites were already covered with the dense gray fog. The fog was rising inexorably and soon it would reach the people who had climbed onto the tops of the broken stalagmites. Evidently there was no hope that its flow would decrease since the gas was spurting from the hole with greater intensity than before.
Artem was supporting Lida, who had fainted, with one arm and holding on to the tip of the stalagmite with his other hand. Disconnected, confused thoughts flashed one after the other through his mind:
How can we get ourselves out of this mess?.. We’re lost, we can’t do anything!… The gas is pouring in… How heavy Lida is. I can’t support her for much longer… My arm has gone to sleep… I mustn’t let her fall… All right, even if I don’t drop her, the damned gas will get us sooner or later anyway… And there’s no way up from here!.. We’ll all suffocate… Diana is evidently still alive though she’s lower than we are… barking…
The situation seemed hopeless indeed. The gas was rising slowly but steadily, and there was something terrifying in this implacable movement…
One of the lamps that had been put on top of the stalagmite threw an even, undisturbed light on the sad picture: the people clinging to the cold, shiny, hard surface of the stalagmites to the last, and the big tawny dog, already covered almost completely by the gray blanket of horrible gas. Diana still gave occasional frightened barks, but they grew less and less frequent. Gray surging waves of gas rose, filling the cave, cutting off all paths of retreat. The gas had already reached the feet of the people perched on top of the stalagmites.
CHAPTER FIVE
A way out of the desperate situation is found which leads to an unexpected and incomprehensible source of subterranean light; the explorers escape through a hole to find woods, steep cliffs and a Scythian arrow; then they discover a crowd of exotically dressed people and witness a confrontation between the chieftain and the soothsayer; Artem interferes to stop the sacrifice but is captured along with his friends.
It seemed to Artem that he had been unconscious for some time. A strange weekness and despair had overwhelmed him. His eyes had closed quite by themselves; his head drooped lower and lower. But with his trembling hand that had gone numb, he was still holding tight to Lida whose limp body seemed heavier and heavier. The only one of his senses that remained fully alert was his hearing, and what is more it even seemed sharper. Artem heard every word the two older men said very distinctly; every little sound around him came in loud and clear; but he could neither respond nor move. It looked as though a thick covering had been thrown over everything. Under this covering were he and Lida whom he was holding… but no… she was moving away… And at some indefinite distance apart were the rest. Then Artem heard the voice of Ivan Semenovich: