Kar — or Bittman — suddenly made a frantic leap. He was seeking to reach the leather suitcase back in the plane cabin.

He brought up against Doc’s bronze arm as against a stone wall. He struck at Doc repeatedly. He missed each time, for the bronze form seemed to vanish under his fists, so quickly did it move.

Increased terror seized the man. His eyes rolled desperately.

"You’ll never kill me!" he snarled.

Strange lights glowed in Doc Savage’s golden eyes.

"You are right," he agreed. "I could never kill with my bare hands a man who saved my father’s life. But do not think you shall escape with your crimes because of that! You will receive your punishment!"

Kar rolled his eyes again. He didn’t know what fate Doc planned for him. But it could be nothing pleasant.

Suddenly the master villain dived headlong through the plane window!

TWO hundred feet below the ship, the man cracked his parachute. It bloomed wide, a clean white bulb in the sinister gray of the crater atmosphere.

Doc Savage gave the oncoming wall of the crater a glance. It was only two minutes away now. Back into the cabin, he flung. He got the leather suitcase at which Oliver Wording Bittman had glanced so longingly.

He did not open the suitcase. The contents might have interested him not at all, judging by his actions.

The speeding plane whipped over in a vertical bank under his mighty hand. It had been almost against the crater wall. The ship seemed to slam against the cliff, then leap away.

Doc’s golden eyes ranged downward. They were a cold gold now, determined. They judged accurately.

Doc dropped the suitcase overside.

The piece of luggage revolved slowly as it fell. It hit just below the lava dike which confined the great lake of boiling-hot mud. It burst.

It had contained Kar’s supply of the Smoke of Eternity! The crater wall below the lava dike began a swift dissolving. Vile, repulsive gray smoke climbed upward in growing volume. It was such a cloud as had arisen at the destruction of the sinister pirate ship, Jolly Roger, in the Hudson River.

The smoke pall hid what was happening beneath. The play of electrical sparks made a weird glow within the squirming mass.

Suddenly, from beneath the cloud crawled a brown, smoking torrent. The lava dike confining the lake of super-heated mud had been destroyed. The molten liquid was running into the crater!

Banking, engine moaning, the plane kept clear of the foul gray cloud from the Smoke of Eternity. Doc’s golden eyes searched. They found what they sought.

Kar! The river of boiling mud overtook him swiftly. The man tried to run. He held his own for a time. Then one of the giant hopping horrors of the crater, the greatest killing machine nature ever made, confronted him. The tyrannosaurus started for Kar with great, bloodthirsty bounds.

Kar chose the easier of two deaths — he let the hideous reptilian giant snap his life out with a single bite.

But an instant later, the wall of hot mud rushed upon the prehistoric monster. The stupid thing took a gigantic leap — deeper into the cooking torrent. It went down. It rolled over slowly, kicking in a feeble way with its huge, three-toed feet.

Thus perished Kar — or Oliver Wording Bittman, the famous taxidermist — and the colossus of reptiles which had devoured him.

DOC held the plane wide open back across the crater. He landed on the narrow runway among the great lumps of stone which had, centuries ago, caved from the cliff.

Renny, Ham, Monk, Johnny, Long Tom — all five piled into the plane on the double-quick.

Doc took off again.

"Look!" Johnny muttered.

The ruptured lake seemed to contain an inexhaustible supply of boiling mud. It still poured forth. It was flooding the floor of the ghastly crater! The monsters existing there were being enveloped.

And the surviving Kar gunman would perish with them! Nothing could save him.

Steam poured upward. It was thickening in the mouth of the crater over their heads — forming a smudge which less and less sunlight penetrated. The growing darkness, the remorseless progress of the mud flood, the antics of the grisly reptilian giants, gave the tableau the aspect of another Judgment Day.

"Talk about your sights!" Monk muttered.

Then they fell silent. They were thinking of that arch-fiend, Oliver Wording Bittman, who had deceived them. The fellow was responsible for their recent capture. He had signaled his men where to attack.

From the very first, he had misled them. From the moment when he came to them with a scratch on his chest which he must have made himself and a clever story of being shot at!

They were amazed at the cunningness of Bittman’s acting. The man had been a master to deceive them as he had.

Even Doc had not seen through Bittman’s fiendish double-dealing until they had reached this crater. But that was understandable. The affection between Doc and his father was extremely great. And Bittman, as a man who had saved the life of Doc’s father, had received Doc’s gratitude. It had been hard for Doc to look to such a man as an evil villain.

"What about the Smoke of Eternity?" questioned Monk suddenly.

For answer, Doc leveled a bronze beam of an arm. They followed his gesture with their eyes.

The region of strange rocks, where Kar must have mined the unknown element or substance to make the Smoke of Eternity, had already been buried by the hot mud flow. It would never be mined now!

Monk looked curiously at Doc Savage.

"Do you know what that stuff — the Smoke of Eternity — was?" he inquired.

N="JUSTIFY"

Doc did not answer immediately. But at length, "I have the theory which grew out of my analysis of the metal which was impervious to the dissolving substance. That theory, I am sure, is near the truth. And that is why I deliberately released the flood of mud."

"Huh?" Monk was puzzled.

"The Smoke of Eternity can never be made without the rare substance which Kar mined here. And the supply of the stuff is now buried hopelessly. As for what the substance was, no one shall ever know. I intend to keep my theories to myself."

Monk nodded. "Guess I see the reason for that."

"The world can get along without the Smoke of Eternity!" Doc’s voice seemed to fill all the plane.

The ship rammed its howling propellers into steam. Up and up, it climbed. The heat nearly took off their skin. But only for a while; it became cooler at last.

So suddenly that it was like a gush of flame into their faces, they were in brilliant sunlight. Their eyes, becoming adapted to the glare, picked up the coral atoll some fifty miles distant.

"No need of even landing there!" Doc decided.

He banked the plane for New Zealand. Ample fuel for the flight sloshed in the gas tanks, thanks to Kar’s foresight.

"From New Zealand to San Francisco by steamer will just about give us time to get the prehistoric reptiles out of our hair!" grinned the irrepressible Monk. "And maybe somethin’ else will turn up soon."