For a few minutes slight tappings came from within, as if a wrench or a screwdriver were being used. Then the tappings stopped, and all was silence.

A choke, a starting cough, came from beneath the sphere. A torrent of rushing sound burst out, and spears of orange flame spurted from the bottom and splashed up its sides, bathing it in fierce, brilliant light. It stirred. Then, slowly and smoothly, the great ball of metal raised up.

It hit the edge of the hole in the ceiling, and hung there, hesitating. Side-rockets flared, and the sphere angled over. Then it slid, roaring, through the hole.

Swiftly the spots of orange from its rocket-tube exhausts died to pin-points. There were now almost twenty of them. And soon these pin-points wavered, and vanished utterly.

Then there was only blackness in the hole that went up to the surface.

Blackness in the hole, calm night on the desert above--and silence, as if the cavern were brooding on the puny figures and strange machines that had for the first time dared invade its solitude, in the realms four miles within the earth....

The Lake of Light

_By Jack Williamson_

[Ill.u.s.tration: _The monster emanated power, sinister, malevolent power._]

[Sidenote: In the frozen wastes at the bottom of the world two explorers find a strange pool of white fire--and have a strange adventure.]

The roar of the motor rang loud in the frosty air above a desert of ice. The sky above us was a deep purple-blue; the red sun hung like a crimson eye low in the north. Three thousand feet below, through a hazy blue mist of wind-whipped, frozen vapor, was the rugged wilderness of black ice-peaks and blizzard-carved hummocks of snow--a grim, undulating waste, black and yellow, splotched with crystal white. The icy wind howled dismally through the struts. We were flying above the weird ice-mountains of the Enderby quadrant of Antarctica.

That was a perilous flight, across the blizzard-whipped bottom of the world. In all the years of polar exploration by air, since Byrd's memorable flights, this area had never been crossed. The intrepid Britisher, Major Meriden, with the daring American aviatrix whom the world had known as Mildred Cross before she married him, had flown into it nineteen years before--and like many others they had never returned.

Faintly, above the purring drone of the motor, I heard Ray Summers'

shout. I drew my gaze from the desolate plateau of ice below and leaned forward. His lean, fur-hooded face was turned back toward me. A mittened hand was pointing, and thin lips moved in words that I did not hear above the roar of the engine and the scream of the wind.

I turned and looked out to the right, past the shimmering silver disk of the propeller. Under the blue haze of ice-crystals in the air, the ice lay away in a vast undulating plain of black and yellow, broken with splotches of prismatic whiteness, lying away in frozen desolation to the rim of the cold violet sky. Rising against that sky I saw a curious thing.

It was a mountain of fire!

Beyond the desert of ice, a great conical peak pointed straight into the amethystine gloom of the polar heavens. It was brilliantly white, a finger of milky fire, a sharp cone of pure light. It shone with white radiance. It was brighter, far brighter, than is the sacred cone of Fujiyama in the vivid day of j.a.pan.

For many minutes I stared in wonder at it. Far away it was; it looked very small. It was like a little heap of light poured from the hand of a fire-G.o.d. What it might be, I could not imagine. At first sight, I imagined it might be a volcano with streams of incandescent lava flowing down the side. I knew that this continent of mystery boasted Mt. Erebus and other active craters. But there was none of the smoke or lurid yellow flame which accompanies volcanic eruptions.

I was still watching it, and wondering, when the catastrophe took place--the catastrophe which hurled us into a mad extravaganza of amazing adventure.

Our little two-place amphibian was flying smoothly, through air unusually good for this continent of storms. The twelve cylinders of the motor had been firing regularly since we took off from Byrd's old station at Little America fifteen hours before. We had crossed the pole in safety. It looked as if we might succeed in this attempt to penetrate the last white spot on the map. Then it Happened.

A sudden crack of snapping metal rang out sharp as a pistol report. A bright blade of metal flashed past the wing-struts, to fall in a flashing arc. The motor broke abruptly into a mad, deep-voiced roar.

Terrific vibration shook the ship, until I feared that it would go to pieces.

Ray Summers, with his usual quick efficiency, cut the throttle.

Quickly the motor slowed to idling speed; the vibration stopped. A last cough of the engine, and there was no sound save the shrill screaming of the wind in the gloomy twilight of this unknown land beyond the pole.

"What in the devil!" I exclaimed.

"The prop! See!" Ray pointed ahead.

I looked, and the dreadful truth flashed upon me. The steel propeller was gone, or half of it at least. One blade was broken off at a jagged line just above the hub.

"The propeller! What made it break? I've never heard--"

"Search me!" Ray grinned. "The important thing is that it did. It was all-metal, of course, tested and guaranteed. The guarantee isn't worth much here. A flaw in the forging, perhaps, that escaped detection.

And this low temperature. Makes metal as brittle as gla.s.s. And the thing may have been crystallized by the vibration."

The plane was coming down in a shallow glide. I looked out at the grim expanse of black ice-crags and glistening snow below us, and it was far from a comforting prospect. But I had a huge amount of confidence in Ray Summers. I have known him since the day he appeared, from his father's great Arizona ranch, to be a freshman in the School of Mines at El Paso, where I was then an instructor in geology. We have knocked about queer corners of the world together for a good many years. But he is still but a great boy, with the bluff, simple manners of the West.

"Do you think we can land?" I asked.

"Looks like we've got to," he said, grimly.

"And what after that?"

"How should I know? We have the sledge, tent, furs. Food, and fuel for the primus to last a week. There's the rifle, but it must be a thousand miles to anything to shoot. We can do our best."

"We should have had an extra prop."

"Of course. But it was so many pounds, when every pound counted. And who knew the thing would break?"

"We'll never get out on a week's provisions."

"Not a shot! Too bad to disappoint Captain Harper." Ray grinned wanly.

"He ought to have the _Albatross_ around there by this time, waiting for us." The _Albatross_ was the ship which had left us at Little America a few months before, to steam around and pick us up at our destination beyond Enderby Land. "We're in the same boat with Major Meriden and his wife--and all those others. Lost without a trace."

"You've read Scott's diary--that he wrote after he visited the pole in 1912--the one they found with the bodies?"

"Yes. Not altogether cheerful. But we won't be trying to get out. No use of that." He looked at me suddenly, grinning again. "Say, Jim, why not try for that shining mountain we saw? It looks queer enough to be interesting. We ought to make it in a week."

"I'm with you," I said.

I did not speak again, for the jagged ice-peaks were coming rather near. I held my breath as the little plane veered around a slender black spire and dropped toward a tiny sc.r.a.p of smooth snow among the ice-hummocks. I might have spared my anxiety. Under Ray's consumately skilful piloting, the skids struck the snow with hardly a shock. We glided swiftly over the ice and came to rest just short of a yawning creva.s.se.

"Suppose," said Ray, "that we spend the first night in the plane. We are tired already. We can keep warm here, and sleep. We've plenty of ice to melt for water. Then we're off for the shining mountain."

I agreed: Ray Summers is usually right. We got out the sledge, packed it, took our bearings, and made all preparations for a start to the luminous mountain, which was about a hundred miles away. The thermometer stood at twenty below, but we were comfortable enough in our furs as we ate a scanty supper and went to sleep in the cabin of the plane.

We started promptly the next morning, after draining the last of the hot chocolate from our vacuum bottles, which we left behind. We had a light but powerful sporting rifle, with telescopic sights, and several hundred rounds of ammunition. Ray put them in the pack, though I insisted that we would never need them, unless a quick way out of our predicament.

"No, Jim," he said. "We take 'em along. We don't know what we're going to find at the shining mountain."