At the very outset, soon after leaving the oasis of Tchertchen, one member of the party had died from gangrene caused by the vicious bite of a Bactrian camel. Later on, a second, seized by a cramp while swimming in the shallow Tarim River, near the reedy marshes of Lob-nor, that strange remnant of a vast inland sea, had drowned before his companions could reach him. A third had died of some mysterious fever. Then in the desert south of the Tarim, where Furnham and Langley still persisted in a futile effort to locate the lost city, their Mongol guides had deserted them, taking all the camels and most of the provisions, and leaving to the two men only their rifles, their canteens, their other personal belongings, the various antique relics they had amassed, and a few tins of food.
The desertion was hard to explain, for the Mongols had heretofore shown themselves reliable enough. However, they had displayed a queer reluctance on the previous day, had seemed unwilling to venture further among the endless undulations of coiling sand and pebbly soil.
Furnham, who knew the language better than Langley, had gathered that they were afraid of something, were deterred by superstitious legends concerning this portion of the Lob-nor Desert. But they had been strangely vague and reticent as to the object of their fear; and Furnham had learned nothing of its actual nature.
Leaving everything but their food, water and rifles to the mercy of the drifting sands, the men had started northward toward the Tarim, which was sixty or seventy miles away. If they could reach it, they would find shelter in one of the sparse settlements of fishermen along its shores; and could eventually make their way back to civilization.
It was now afternoon of the second day of their wanderings. Langley had suffered most, and he staggered a little as they went on beneath the eternally cloudless heavens, across the glaring desolation of the dreary landscape. His heavy Winchester had become an insufferable burden, and he had thrown it away in spite of the remonstrance of Furnham, who still retained his own weapon.
The sun had lowered a little, but burned with gruelling rays, tyrannically torrid, through the bright inferno of stagnant air. There was no wind, except for brief and furious puffs that whirled the light sand in the faces of the men, and then died as suddenly as they had risen. The ground gave back the heat and glare of the heavens in shimmering, blinding waves of refraction.
Langley and Furnham mounted a low, gradual ridge, and paused in sweltering exhaustion on its rocky spine. Before them was a broad, shallow valley, at which they stared in a sort of groggy wonderment, puzzled by the level and artificial-looking depression, perfectly square, and perhaps a third of a mile wide, which they descried in its center. The depression was bare and empty, with no sign of ruins, but was lined with numerous pits that suggested the ground-plan of a vanished city.
The men blinked, and both were prompted to rub their eyes as they peered through flickering heat-waves; for each had received a momentary impression of flashing light, broken into myriad spires and columns, that seemed to fill the shallow basin and fade like a mirage.
Still mindful of their quarrel, but animated by the same unspoken thought, they started down the long declivity, heading straight toward the depression. If the place were the site of some ancient city, they might possibly hope to find a well or water-spring.
They approached the basin’s edge, and were puzzled more and more by its regularity. Certainly it was not the work of nature; and it might have been quarried yesterday, for seemingly there were no ravages of wind and weather in the sheer walls; and the floor was remarkably smooth, except for the multitude of square pits that ran in straight, intersecting lines, like the cellars of destroyed or unbuilt houses. A growing sense of strangeness and mystery troubled the two men; and they were blinded at intervals by the flash of evanescent light that seemed to overflow the basin with phantom towers and pillars.
They paused within a few feet of the edge, incredulous and bewildered. Each began to wonder if his brain had been affected by the sun. Their sensations were such as might mark the incipience of delirium. Amid the blasts of furnace-like heat, a sort of icy coolness appeared to come upon them from the broad basin. Clammy but refreshing, like the chill that might emanate from walls of sunless stone, it revived their fainting senses and quickened their awareness of unexplained mystery.
The coolness became even more noticeable when they reached the very verge of the precipice. Here, peering over, they saw that the sides fell unbroken at all points for a depth of twenty feet or more. In the smooth bottom, the cellar-like pits yawned darkly and unfathomably. The floor about the pits was free of sand, pebbles or detritus.
“Christ! What do you make of that?” muttered Furnham to himself rather than to Langley. He stooped over the edge, staring down with feverish and inconclusive speculations. The riddle was beyond his experience—he had met nothing like it in all his researches. His puzzlement, however, was partly submerged in the more pressing problem of how he and Langley were to descend the sheer walls. Thirst—and the hope of finding water in one of the pits—were more important at that moment than the origin and nature of the square basin.
Suddenly, in his stooping position, a kind of giddiness seized him, and the earth seemed to pitch deliriously beneath his feet. He staggered, he lost his balance, and fell forward from the verge.
Half-fainting, he closed his eyes against the hurtling descent and the crash twenty feet below. Instantly, it seemed, he struck bottom. Amazed and incomprehending, he found that he was lying at full length, prone on his stomach in mid-air, upborne by a hard, flat, invisible substance. His outflung hands encountered an obstruction, cool as ice and smooth as marble; and the chill of it smote through his clothing as he lay gazing down into the gulf. Wrenched from his grasp by the fall, his rifle hung beside him.
He heard the startled cry of Langley, and then realized that the latter had seized him by the ankles and was drawing him back to the precipice. He felt the unseen surface slide beneath him, level as a concrete pavement, glib as glass. Then Langley was helping him to his feet. Both, for the nonce, had forgotten their misunderstanding.
“Say, am I bughouse?” cried Langley. “I thought you were a goner when you fell. What have we stumbled on, anyhow?”
“Stumbled is good,” said Furnham reflectively, as he tried to collect himself. “That basin is floored with something solid, but transparent as air—something unknown to geologists or chemists. God knows what it is, or where it came from or who put it there. We’ve found a mystery that puts Kobar in the shade. I move that we investigate.”
He stepped forward, very cautiously, still half-fearful of falling, and stood suspended over the basin.
“If you can do it, I guess I can,” said Langley, as he followed. With Furnham in the lead, the two began to cross the basin, moving slowly and gingerly along the invisible pavement. The sensation of peering down as if through empty air was indescribably weird.
They had started midway between two rows of the dark pits, which lay about fifty feet apart. Somehow, it was like following a street. After they had gone some little distance from the verge, Furnham deviated to the left, with the idea of looking directly down into one of these mysterious pits. Before he could reach a vertical vantage-point, he was arrested by a smooth, solid wall, like that of a building.