He spoke his thoughts to Jim. "There must be a tunnel opening somewhere very near us," he concluded. "But I--Good heavens!"

Both crouched in wary alarm, spears held for a thrust, if necessary, at the frightful thing approaching them from the near jungle.

Thirty feet long, it was, and six feet through, a blunt-ended, untapered serpent that glistened a moist crimson color in the rays of the sun. The trees quaked and rocked as it brushed against them in its deliberate advance. Dead leaves many feet across and too heavy for the combined efforts of both men to have budged, were pushed lightly this way and that as the monster moved. The very ground seemed to shake under its appalling weight.

"If _that_ comes after us," breathed Jim, "we're through!"

But now Denny drew a long breath of relief.

"Be still," he said. "Make no sound, and no move, and it will probably pa.s.s us by. It's blind, and couldn't harm us in any way--unless it rolled on us."

The two stood motionless while the nightmare serpent crashed by. Then, with the earthworm fading into the distance, they resumed their hunt for the near tunnel entrance.

Jim, whose eyes were more accustomed to searching jungle depths, finally saw it--a black hole leading down into a small hill about two hundred yards ahead of them. He pointed.

"There we are. Come on."

Laboriously they set out toward it. Laboriously because at every step some almost insuperable hurdle barred their way. A fallen gra.s.s stalk was a problem; sometimes they had to curve back on their tracks for sixty or eighty feet in order to get around it. A dead leaf, drifted there from the trees near at hand, was almost a calamity, necessitating more circuitous maneuvering.

With every yard the realization of the stark peril that was now theirs increased.

A gra.s.shopper, blundering to the ground within a rod of them, nearly crushed them with its several tons of weight. A b.u.mblebee, as big as a flying elephant and twice as deadly, roared around them for several minutes as though debating whether or not to attack them, and finally roared off leaving them shaken and pale. But the most startling and narrow of their narrow escapes occurred an instant after that.

They had paused for an instant, alert but undecided, to stare at a coldly glaring spider that was barring their path. It was a small spider, barely more than waist-high. But something in its malevolent eyes made the two men hesitate about attacking it. At the same time it was squatting in the only clear path in sight, with tangles of stalks and leaves on either side. A journey around the ferocious brute might be a complicated, long-drawn-out affair.

Their problem was decided for them.

Overhead, suddenly roared out a sound such as might have been made by a tri-motored Fokker. There was a flash of yellow. The roar increased to an ear-shattering scream. Something swooped so breathlessly and at the same time so ponderously that the men were knocked flat by the hurricane of disturbed air.

A fleeting struggle ensued between some vast yellow body and the unfortunate spider. Then the spider, suddenly as immobile as a lump of stone, was drawn up into the heavens by the roaring yellow thing, and disappeared. A wasp had struck, and had obtained another meal.

"Thank G.o.d that thing had a one-track mind, and was concentrating on the spider," said Jim, with a rather humorless laugh.

Dennis was silent. He was beginning to realize that he knew too much about insects for his peace of mind. To Jim, insects had always heretofore been something to brush away or step on, as the circ.u.mstance might indicate. He had no idea, for example, of exactly what fate it was he had just missed. But Denny knew all about it.

He knew that if the wasp had chosen either of them, the chosen one would have felt a stabbing thing like a red-hot sword penetrate to his vitals.

He knew that swift paralysis would have followed the thrust. He knew that then the victim would have been taken back, helpless and motionless as the spider was, to be laid side by side with other helpless but still conscious victims in the fetid depths of the wasp's nest. And he knew that finally an egg would have been laid on the victim's chest; an egg that would eventually hatch and deliver a bit of life that would calmly and leisurely devour the paralyzed food supply alive.

"Let's hurry," he suggested, glancing up to see if any more wasps were hovering about.

The lowering tunnel mouth was very near now. Barely twenty yards away.

What with the crowding monsters around them, the tunnel began to look like a haven. Almost at a run, they continued toward it.

Then a commotion like that which might be made by a mighty army sounded in the underbrush behind them. Dennis looked back over his shoulder.

"Hurry!" he gasped, suddenly accelerating his pace into frank flight.

"Ants...."

Jim glanced back, too--and joined Denny in his flight. Pouring toward them at express train speed, flinging aside fallen stalks, climbing over obstructions as though no obstructions were there, was coming a grim and armored horde. Far in the lead, probably the one that had seen the men first and started the deadly chase, was a single ant.

The solitary leader was a monster of its kind. As tall as Jim, clashing in its h.o.r.n.y armor, it rushed toward the fugitives.

"It's going to reach the tunnel before we do," Jim panted. "We've got to kill the thing--and do it before the rest get to us...."

The monster was on them. Blindly, ferociously it hurled its bulk at the things that smelled like termites however little they resembled them.

The termite-paste was, in this instance, the most deadly of challenges.

Jim stepped to the fore, with his spear point slanted to receive the onslaught, spear b.u.t.t grounded at his feet.

Whether the six-legged horror would have had wit enough to comprehend the nature of the defense offered, and would have striven to circ.u.mvent it, had time been given it, is a question that will never be answered.

For the thing wasn't given the time.

In mid-air it seemed to writhe and try to change the direction of its leap. But it was on the point and had transfixed itself before its intelligence, however keen, could have functioned.

The fight, though, was by no means over. With five feet of steel piercing it through, it whirled with hardly abated vitality toward Dennis. Its gargoyle head came close and closer.

Dennis sprang sideways along its length, lifted the pointed bar he held, and dashed it down on what looked to him a vital spot--the unbelievably slender trunk that held its spatulate abdomen to its armored chest.

There was a crack as the bar smashed down on the weak point. The monster sank quivering to the ground. An instant later it was up, but now its movements were dazed and sluggish as it dragged its half-paralyzed abdomen after it, and fumbled and caught on the heavy bar that transfixed it.

Jim caught the bar and tugged it. "My spear!" he cried. "Denny--help!"

Together the two wrenched to jerk the spear loose from the h.o.r.n.y armor of the dying ant. The rest of the pack were very near now.

"We'll have to let it go...." panted Denny.

But at that instant their desperate efforts tore it loose from the convulsively jerking hulk. They darted into the tunnel mouth with the racing horde scarcely twenty yards behind them.

Without hesitation the ants poured in after them. Jim and Dennis leaped forward, in pitch darkness, now and then b.u.mping heavily against a wall as the tunnel turned, but having at least no trouble with their footing: the floor was as smooth as though man-made.

Behind them they could hear the armored horde crashing along in the blackness. The smashing noise of their progress was growing louder. The two had run perhaps fifty yards in the darkness. Another fifty, and they would be caught!

But now, just as their eyes--sharpened also by the danger they were in--began to grow accustomed to the gloom, they saw ahead of them a thing that might have stepped straight out of a horrible dream.

Six feet of vulnerable, unarmored body, amply protected by h.o.r.n.y head and shoulders and ten feet of awful, scissor-mandibles, faced them. The creature was doing a strange sort of war dance, swaying its terrible bulk back and forth rhythmically, while its feet remained immovable. An instant it did this, then it charged at the two men. Simultaneously the crashing of the fierce horde behind sounded with appalling nearness--the noise and odor of the ants preventing the huge termite guard in front of the men from recognizing and approving the smell of the termite-paste that covered their bodies.

"Follow me!" snapped Denny, remembering that the hideous attacking thing before them was blind, and gaining from that knowledge swift inspiration.