The air reptile tumbled away. Johnny lifted a grateful face.

"My shots didn’t seem to do much good!" he called.

"Try for the neck or eyes!" Doc replied.

Strong air currents now made themselves felt. The parachutes were swept rapidly to one side, away from the edge of the crater.

Directly below, Doc’s gaze rested upon a remarkable sight. It would have been a fearsome sight, too, except that his practiced eye told him they were going to be carried clear of danger by the wind.

A mud lake, narrow, but spreading for thousands of rods along the crater side, was below. A crust, resembling asphalt and apparently very hard, covered the lake. This must be nearly red-hot, judging from the heat of the moist air which rushed upward.

Probably this amazing mud lake reached in a horseshoe shape halfway around the crater. Certainly, the ends were lost to sight.

A natural lava wall confined it to the crater side, well above the floor.

The ruined plane fell into the mud lake. Its weight broke the crust. Instantly, there was a great eruption at that point. A geyser column of scalding, lavalike mud shot hundreds of feet upward, driven by steam pressure gathered beneath the crust. Steam itself now exuded. It made a deafening roar.

A thunderous crackling swept over the mud lake as the crust settled. From countless points came minor eruptions. The steam, squirting outward and upward, enveloped the falling parachutes.

They could not see where they were landing!

THE parachutes pitched like leaves in the disturbed air. Not only did the gushing, superheated winds carry them clear of the mud lake, but they were flung far out on the crater floor.

Doc, compact machine gun in hand, waited. His golden eyes sought to pierce the steamy world. The air was so hot as to be near sickening. It possessed a weird, unusual fragrance.

It was like the atmosphere within a greenhouse — impregnated with the odor of rankly growing plants.

The thunderous crackling from the mud lake subsided as quickly as it began.

Suddenly a shocking din arose below. A piercing, trumpetlike cry quavered. A coarse, beastly bawling joined it. Tearing of branches, the hollow pops of green timber breaking, the dull reverberations of great bodies thumping the earth, made a nightmarish discord. It was a sound to make the flesh creep.

"Renny! Monk! The rest of you!" Doc’s resonant tones pealed through the hobgoblin clamor. "Spill air from one side of your ‘chute and try to avoid the vicinity of that noise!"

From below the abyss of steam, where his men were lost from view, came replying shouts. But there was little time to comply.

The frond of an immense plant brushed past Doc’s mighty bronze form. The plant was of colossal size. It seemed to be something on the order of a tree fern. So towering was it that there elapsed a distinct interval before the parachute reached the ground.

Doc landed in a tangle of creepers and low trees which looked like ordinary evergreens. More ferns, these much smaller, made a spongy mat of the whole. It was like descending in a pile of enormous, coarse green cobwebs.

Shucking off the parachute harness, Doc sprang to less tangled footing. The ground was a soft mulch underfoot — as though fresh plowed.

The hideous uproar they had heard from the air had subsided! A low rumble had replaced it. This rumble seemed to be some great monster in flight! The sound was already some distance away, and departing like an express train.

Of a sudden, there came into the surrounding air the low, trilling note that was part of Doc. Now, more than ever, was that sound suggestive of a strange bird of the jungle. It might have been a wind filtering through the ghostly, fantastic forest around about.

And as always, that inspiring sound conveyed some definite meaning. This time it was — be silent! There is danger near!

Doc knew that grisly, caterwauling concert he had heard while in the air meant a fight between behemoths of a prehistoric reptilian world. He recognized the plant forms about him. Some had been extinct for ages.

Doc had dropped into a land which was very much as it had been countless ages ago. A fearsome, bloodcurdling land where survival of the fiercest was the only law!

Doc’s strange sound trailed away in echoes that, although they possessed no definite tune, were entrancingly musical in their quality.

Now he could hear some gigantic horror breathing near by! The breathing was hurried, as though the terrible thing had been engaged in strife. The sounds were hollow, very loud — almost like the pant of an idling freight locomotive!

Suddenly vegetation swished and crashed as the monster got into motion.

It was charging Doc!

Doc’s mighty bronze figure flashed sidewise, moving with a speed such as it possibly had never before attained. But as he changed position, his golden eyes were sharpened for sight of the peril that rushed him.

He saw it — as fearful and loathsome a sight as human eyes ever beheld!

THE shocking size of the horror was apparent. It bulged out of the steam like a tall house. It hopped on massive rear legs, balancing itself by a great tail, kangaroolike.

The two forelegs were tiny in proportion — like short strings dangling. Yet those forelegs that seemed so small were thicker through by far than Doc Savage’s body!

The revolting odor of a carnivorous thing accompanied the dread apparition. The stench was of decaying gore. The hide of the monster had a pebbled aspect, somewhat like a crocodile. Its claws were frightful weapons of offense, being of such proportions as to easily grasp and crush a large bull.

Perhaps the most ghastly aspect of the thing were the teeth. They armored a blunt, revolting snout of a size as stupendous as the rest of the hopping terror.

So great was the weight of the thing that its feet sank into the spongy earth the depth of a tall man at each step.

"What is it, Doc?" Monk shouted.

"Tyrannosaurus!" Doc answered him. "Look lively!"

The monster reptile, after bounding past Doc, stopped. An instant following Monk’s called words, the beast charged the sound of his voice.

"Dodge it, Monk!" Doc barked. "Dodge it! The thing probably has a very sluggish brain. That has always been supposed to be a trait of prehistoric dinosaurs. Get out of its path, and several seconds will elapse before it can make up its mind to follow you!"

Shrubs ripped. A stream of shots erupted from Monk’s compact machine gun. Bushes fluttered again. Monk gave a bark of utter awe.

"Monk!" Doc called. "You shouldn’t have tried to shoot it! Nothing less than a cannon can even trouble that baby!"

"You’re tellin’ me!" Monk snorted. "Man! Man! The bat of a thing that chewed the wing of our plane was a pretty little angel alongside this cuss! O-o-op!Here it comes again!"

The noisy charge, and Monk’s dodging, was repeated. Monk did not fire this time. He knew Doc was right. The little machine guns, efficient though they might be, would bother this reptilian monster less than beans thumbed at an alligator.

"Made it!" Monk called.

"Then keep that noisy mouth shut!" snapped the waspish Ham. "It rushes the sound of your voice!"

The steam — it had come from the eruption of the mud lake — was rapidly disappearing. The ferocious tyrannosaurus would soon be able to search them out with its eyes!

"All of you get over with Monk!" Doc shouted.

He nimbly evaded the great reptile as it sought his voice, then worked over until Monk’s anthropoid figure loomed in the dispersing steam.

Oliver Wording Bittman was there. The taxidermist’s face was the color of a soiled handkerchief. His jaw jerked up and down visibly, but he had his tongue thrust between his teeth, fearful lest their chattering attract the awful bounding reptile.