Chapter I: Front Matter

THE SECOND SHELL

By JACK WILLIAMSON

_By the Author of "The Alien Intelligence," "The Girl from Mars"_

_Here the well-known author of "The Alien Intelligence" and other
thrilling stories presents his latest symphony, a fine piece of
aerial fiction._

_Few authors have Jack Williamson's knack to pack their stories
with so much adventure and with so much imaginative science. And
while it may be fantastic today, most of it we know, sooner or
later, will have become reality._

_All scientists for decades have been wondering what the mysterious
Heaviside Layer is. Radio engineers know of the Heaviside Layer
from its effect on radio waves. It is very much of a fact, yet no
one has ever been able to get near it, due to its distance above
the surface of the earth, and till we have penetrated it, we cannot
be sure what lies above it._

_We know you will enjoy the present story, which easily bears
re-reading from time to time._

[Transcriber's Note: This etext was produced from
Air Wonder Stories November 1929
Extensive research did not uncover any evidence that
the U.S. copyright on this publication was renewed.]

It was two o'clock in the morning of September 5, 1939. For a year and a half I had been at work on the San Francisco _Times_. I had come there immediately after finishing my year's course at the army officers' flying school at San Antonio, on the chance that my work would lead me into enough tong wars and exciting murder mysteries to make life interesting.

The morning edition had just been "put to bed" and I was starting out of the office when the night editor called me to meet a visitor who had just come in. The stranger came forward quickly. Roughly clad in blue shirt and overalls, boots, and Stetson, he had the bronze skin, clear eyes, and smooth movements of one who has spent his life out-of-doors.

He stopped before me and held out his hand with a pleasant smile. I saw that his hair was gray; he was a little older than I had thought at first--fifty, perhaps. I liked the fellow instinctively.

"Robert Barrett?" he questioned in a pleasant drawl. I nodded.

"I'm Bill Johnson," he said briefly. "I want to see you. Secret Service business. _Sabe?_" He let me glimpse a badge, and we walked out into the night. As we started down the silent street it occurred to me that I had heard of this man before.

"Are you the William Johnson who unearthed the radio station of the revolutionaries in Mexico in 1917?"

"I guess so. I've been in Mexico thirty years, and I've helped Uncle Sam out a time or two. It's a case like that one, or worse, that I'm up here to see about now. I need a partner. I've been told about you. Are you game for a little adventure?"

"You've found your man."

"They call you 'Tiger Bob Barrett,' don't they?" he said irrelevantly.

"I used to play football."

He laughed. I have always been sensible about that nickname.

"Well, here's the situation. I've been at Vernon's mine in Durango, Mexico. Called El Tigre. Gold and thorium. There's a little mystery--"

"Vernon? Is it Doc Vernon, the scientist. His daughter inherited a mine--"

"_Si, Señor._ Ellen Vernon is some young lady!"

"I knew them at Texas University. I was in Vernon's chemistry class before he went daft on his death ray machine, and left to work on that."

"The Doc is still at work on the machine. In fact, that is a part of the mystery.

"The mine is in an old corner of the desert, about fifty miles south of Mocolynatal--the big mountain. And there's something queer going on about that mountain!

"Ellen got herself a radio set to pass away the time with. She got to picking up strange stuff. Sounds we couldn't make out! Not just a strange lingo. They don't sound like the human voice at all! Strange chirps and squeaks! Doc and I rigged up a directional set, and found that the calls were sent from Mocolynatal.

"The mountain's in sight, to the north of us. I got to watching it, and found out something else. There have been airplanes flying about it--queer red machines with short stubby wings! They flew off mostly to the west. I did a little more investigation, and found that a line of run-down Jap tramp steamers has been hauling cargoes of the-lord-knows-what, and unloading somewhere along the Pacific coast of Mexico--evidently making connections with the red machines.

"Now, the Doc has his machine where he thinks it will be the end of the world if anybody gets hold of it. We've seen one or two of the red planes over the mine, and he is afraid they have found out about it, somehow. He got nervous, and sent me up to see Uncle Sam. It is all news to the State Department, and we are going to investigate.

"One of the Jap tramps is leaving here tomorrow, and there will be a couple of destroyers on the trail, to see what they unload, and where. I've got hold of a new airplane--a queer little machine called the Camel-back, that I'm taking along on board. A jewel for mountain work--you could land it on a handkerchief. I needed a partner, and the Doc told me about you. Want to go along?"

"You bet I do! I've been longing for something to turn up."

"Well, be at the landing field at nine tomorrow--this morning, rather, ready for anything. This may be interesting before we're through. _Buenas Noches._"

A Raid and a Mystery

The old fellow left me, and I walked on toward my apartment, thinking over what I had heard. Dr. Vernon's invention a success at last! I remembered very clearly my days with the nervous, stammering little scientist, always sure that tomorrow would bring the great secret. And I thought of Ellen--indeed, I had often done so in the two years since I had heard from her. I wondered why she and her father had left Austin so suddenly, and why their destination had been kept a secret from all their friends.

As for the matter of the red planes, I could suppose nothing but that the outs in Mexican politics were preparing a little military surprise for the ins. There have been too many military forces raised secretly in Mexico for one of them to be much of a novelty. Then I thought of the queer radio messages. They did not fit in very well. But my mind returned to Ellen again. I thought no more of the red machines. I had no thought--no one on earth had warning--of the terrible force that was rising to menace the world.

In the morning, when I came down to the lobby, I found a curious clamor going. There was a hum of conversation, and people were passing around red-paper "extras". It was five minutes before I could get one to read the screaming headlines:

RED PLANES RAID FACTORY
THREE HUNDRED DEAD
MILLION DOLLAR STOCK OF
THORIUM TAKEN

The account went on to describe the raid, at four o'clock that morning, of a fleet of red airplanes upon the Rogers Gas Mantle Factory, at St. Louis. It was stated that three hundred people had been killed, and that the entire stock of thorium nitrate on hand, worth over a million dollars, had been carried off.

Much of a mystery was made of it. Police had failed to identify three of the four red-uniformed corpses left behind. Fingerprints identified the other as a noted criminal recently out of Leavenworth.

No one seemed to have any idea why the thorium had been taken, since the chief use of that radioactive metal, which is similar to radium, but far less active, is in the manufacture of gas mantles.

It was farther stated that the raiders had released "clouds of a luminous purple gas," which had caused most of the fatalities, and which seemed to have destroyed the gravity of metallic objects about. It was said that the factory building was curiously wrecked, as if the heavy machinery had gone up through the roof.

At first it struck me that this must be simply a newspaper canard. Then I remembered what Bill Johnson had told me of the strange red airplanes in Durango, and of the mystery of the secret radio station. Then I was not so sure. I ate a little breakfast and hurried out to the landing field. I found Bill with a copy of the paper in his hand. His wrinkled face had a look of eager concentration on it.

"Howdy, Bob," he drawled. "This looks interesting. Have you seen it?" I nodded. "It must be the same red planes. Let's get off."

We walked out on the field, where the "Camel-back" plane was waiting. It was the first one I had seen; one of the first models built, I believe. It was based on Cierva's _Autogiro_, or "windmill plane". But there was an arrangement by which the rotating mast could be drawn into the fuselage, the rotation stopped, and the vanes folded to the side, so that the machine, in the air, could be transformed into an ordinary monoplane, capable of a much higher flying speed than the _Autogiro_. When the pilot desired, a touch of a button would release the mast and vanes, and the machine became an _Autogiro_, which could spiral slowly or drop almost perpendicularly to a safe landing on a small spot of ground.

The machine had a further innovation in the shape of a Wright turbine motor. This had but a single important moving part, the shaft which bore the rotors, the flanged wheel that drew the mixture into the combustion chamber, and the propeller. Because of its extreme light weight and high efficiency, the internal combustion turbine engine now promises to come into general use.

The name of the machine, "the Camel-back," was due to the peculiar hump to the rear of the mast, covering the levers for raising and lowering the rotating "windmill."

The plane carried a .50 calibre machine gun in the forward cockpit.

"Get aboard, Bob, and we're off," Bill said as we got on our parachutes. "The tramp weighed anchor at four this morning, and the destroyers left an hour later. We'll be able to pick them up."

Five minutes later our trim little machine was rolling forward with the "windmill" spinning. It swept smoothly upward, Bill moved into gear the device that brought down the mast, and soon we were over the cold gray Pacific, with the city fading into the haze of the blue northern horizon.

Bill was flying the ship, and my thoughts turned back to Dr. Vernon and his daughter. The Doctor was a pudgy, explosive little man, who thought, ate, and breathed science. His short, restless figure always bore the marks of laboratory cataclysms, and his life had been marred by the earlier lack of success in perfecting the terrible machine to which he was devoting his life. I had always thought it strange that a man so mild and tender-hearted should toil so to build a death-dealing instrument, and I wondered what he would do with it now if he had it completed.

It was five years since I had seen Ellen. She had been but a spritely, elfin girl. I remembered her chiefly as having been instrumental, one day at a party, in getting me to drop myself into a supposed easy chair, which turned out to be a tub of ice water.