“What is it?” she whispered, staring at the unstable surface in a kind of horror.
Before he could reply, cries and shouts arose among the tribe behind him, and they all rushed forward, almost sweeping Grôm and A-ya from their feet.
The surface of the barren, all along the edge of the grass land, had given way beneath the weight of the sambur herds, and the front ranks were being engulfed with frantic snortings and awful groans, in what looked like a dense, blackish, glistening ooze. The ranks behind were being forced forward to this awful doom, in spite of their panic-stricken struggles to hold back; and it was the pressure of this battling mass that 307 was creating the horrible, bulging undulation on the plain.
Grôm’s quick intelligence took in the situation on the instant. The naked brown surface beneath the feet of the tribe was nothing more than a thin crust overlying a lake of some dense, dark, strange-smelling liquid.
His first impulse, naturally, was to turn back––and A-ya, with wide eyes of terror, was already dragging fiercely at his elbow. But to turn back was utterly impossible. That way lay the long strip of engulfing pitch, swallowing up insatiably the ranks of the groaning and kicking sambur. There was but one possible way of escape left open, and that was straight ahead.
But would the crust continue to uphold them? Already, under the weight of the whole tribe pressing together, it was beginning to sag hideously. With furious words and blows he tried to make the tribe scatter to right and left, so as to spread the pressure as widely as possible. Perceiving his purpose, A-ya and Loob, and several of the leading warriors, seconded his efforts with frantic vehemence; till in a few minutes the whole tribe, amazed and quaking with awe, was extended like a fan over a front of three or four hundred yards. Seeing that the perilous sagging of the crust was at once relieved, Grôm then ordered the tribe to advance cautiously, keeping the same wide-open formation, while he himself brought up the rear.
But in a few minutes every one, from Grôm downwards, 308 came to a halt irresistibly, in order to watch the monstrous drama unfolding behind them.
For nearly half a mile to either side of their immediate rear, between the still unbroken surface of the dust-brown expanse and the edge of the trampled grassy plain, stretched a sort of canal, perhaps ten paces wide, of brown-black, glistening pitch, beaten up with thrashing antlers, and tossing heads that whistled despairingly through wide nostrils, and heaving, agonizing bulks that went down slowly to their doom. After several ranks of the herd had been engulfed those next behind turned about in terror and fought madly to force their way back from the fatal brink. But the inexorable masses behind them rolled them on backwards, and slowly they too were thrust down into the pitch, till the canal was filled to the brink, and writhed horribly along its whole length. By this time, however, the alarm had spread through the rest of the sambur ranks. By a desperate effort they got themselves turned, and went surging off to the left in a direction parallel to the edge of the plain of death.
Thrilled with the wonder and the horror of it, Grôm drew a deep breath and relaxed the tension of his watching. He was just about to turn and order the tribe forward again, when he was arrested by the sight of a vast cloud of dust rolling up swiftly upon the left flank of the retreating sambur.
A confused cry of alarm went up from the watching tribe, as they saw a forest of waving trunks appear in 309 the front of the dust-cloud. A second or two more and a long array of mammoths emerged along the path of the cloud. Among the mammoths, here and there, raced a black or a white rhinoceros, or a towering, spotted giraffe. Behind this front rank, vague and portentous through the veiling cloud, came further colossal hordes, filling the distance as far as eye could see.