The Ultimate Weapon

by Jr. John W. Campbell

  VIII

  Grimly Buck Kendall looked at the reports. McLaurin stood beside him,Devin sat across the table from him. "What do you make of it, Buck?"asked the Commander.

  "That we have just one island of resistance left on the Jovian worlds.And that will, I fear, vanish. They haven't finished with their arsenalby any means."

  "But what was it, man, what was it that ruined those ships?"

  "Vibration. Somehow--Lord only knows how it's done--they can projectelectric fields. These projected fields are oscillated, and they aretuned in with some parts of the ship. I suspect they are crystals of themetals. If they can start a vibration in the crystals of themetal--that's fatigue, metal fatigue enormously speeded. You know how aquartz crystal oscillator in a radio-control apparatus will break, ifyou work it on a very heavy load at the peak? They simply smash thecrystals of metal in the same way. Only they project their field."

  "Then our toughest metals are useless? Can't something tough, ratherthan hard, like copper or even silver for instance, stand it?"

  "Calcium metal's the toughest going--and even that would break under thebeating those ships give it. The only way to withstand it is to havesuch a mass of metal that the oscillations are damped out. But--"

  The set tuned in on the IP station on Europa was speaking again. "Theships are returning. There are one hundred and twenty-nine by accuratecount. Jorgsen reports that telescopic observation of the dead on thefallen cruiser show them to be a _completely un-human race_! They areof mottled coloring, predominately grayish brown. The ships arereturning. They have divided into ten groups, nine groups of two each,and a main body of the rest of the fleet. The group of eighteen isdescending within range, and we are focusing our beams on them--"

  Out by Europa, ten great UV beams were stabbing angrily toward ten greatinterstellar ships. The metal of the hulls glowed brilliant, anddistorted slowly as the thick walls softened under the heat, and the airbehind pressed against it. Grimly the ten ships came on. Torpedoes werebeing launched, and exploded, and now they had no effect, for the Miranswithin were protected.

  The eighteen grouped ships separated, and arranged themselves in acircle around the fort. Suddenly one staggered as a great puff of gasshot out through the thin atmosphere of Europa to flare brilliantly inthe lash of the stabbing UV beam. Instantly the ship righted itself, andlabored upward. Another dropped to take its place--

  And the great walls of the IP fort suddenly groaned and started in theirwelded joints. The faint, whispering rustle of the crumbling beam wasmurmuring through the station. Engineers shouted suddenly as metersleapt the length of their scales, and the needles clicked softly on thestop pins. A thin rustle came from the atostors grouped in the greatpower room. "Spirits of Space--a revolving magnetic field!" roared theChief Technician. "They're making this whole blasted station a squirrelcage!"

  The mighty walls of eight-foot metal shuddered and trembled. The UVbeams lashed out from the fort in quivering arcs now, they did not holdtheir aim steady, and the magnetic shield that protected them fromatomic bombs was working and straining wildly. Eighteen great shipsquivered and tugged outside there now, straining with all their power toremain in the same spot, as they passed on from one to another themagnetic impulses that were now creating a titanic magnetic vortex aboutthe fort.

  "The atostors will be exhausted in another fifteen minutes," the ChiefTechnician roared into his transmitter. "Can the signals get throughthose fields, Commander?"

  "No, Mac. They've been stopped, Sparks tells me. We're here--and let'shope we stay. What's happening?"

  "They've got a revolving magnetic field out there that would spin aminor planet. The whole blasted fort is acting like the squirrel cage inan induction motor! They've made us the armature in a five hundredmillion horsepower electric motor."

  "They can't tear this place loose, can they?"

  "I don't know--it was never--" The Chief stopped. Outside a terrificroar and crash had built up. White darts of flame leapt a thousand feetinto the air, hurling terrific masses of shattered rock and soil.

  "I was going to say," the Chief went on, "this place wasn't designed forthat sort of a strain. Our own magnetic field is supporting us now,preventing their magnetic field from getting its teeth on metal. Whenthe strain comes--well, they're cutting loose our foundation with atomicbombs!"

  Five UV beams were combined on one interstellar ship. Instantly thegreat machine retreated, and another dropped in to take its place whilethe magnetic field spun on, uninterruptedly.

  "Can they keep that up long?"

  "God knows--but they have a hundred and more ships to send in when thepower of one gives out, remember."

  "What's our reserve now?"

  The Chief paused a moment to look at the meters. "Half what it was tenminutes ago!"

  Commander Wallace sent some other orders. Every torpedo tube of thestation suddenly belched forth deadly, fifteen-foot torpedoes, most ofthem mud-torpedoes, torpedoes loaded with high explosive in the nose, adelayed fuse, and a load of soft clinging mud in the rear. The mud wouldflow down over the nose and offer a resistance foot-hold for theexplosive which empty space would not. Four hundred and three torpedoes,equipped with anti-magnetic apparatus darted out. One hundred and fourpassed the struggling fields. One found lodgement on a Miran ship, andcrushed in a metal wall, to be stopped by a bulkhead.

  The Chief engineer watched his power declining. All ten UV beams wereunited in one now, driving a terrible sword of energy that made theattacked ship skip for safety instantly, yet the beams were all butuseless. For the Miran reserves filled the gap, and the magnetic tornadocontinued.

  For seventeen long minutes the station resisted the attack. Then thelast of the strained mercury flowed into the receivers, and the vastpower of the atostors was exhausted. Slowly the magnetic fieldsdeclined. The great walls of the station felt the clutching lines offorce--they began to heat and to strain. A low, harsh grinding becameaudible over the roar of the atomic bombs. The whole structure trembled,and jumped slightly. The roar of bombs ceased suddenly, as the stationjerked again, more violently. Then it turned a bit, rolled clumsily.Abruptly it began to spin violently, more and more rapidly. It startedrolling clumsily across the plateau--

  A rain of atomic bombs struck the unprotected metal, and the eighthbreached the walls. The twentieth was the last. There was no longer anIP station on Europa.

  "The difference," said Buck Kendall slowly, when the reports came infrom scout-ships in space that had witnessed the last struggle, "betweenan atomic generator and an atomic power-store, or accumulator, isclearly shown. We haven't an adequate _source_ of power."

  McLaurin sighed slowly, and rose to his feet. "What can we do?"

  "Thank our lucky stars that Faragaut here, and I, bought up all themercury in the system, and had it brought to Earth. We at least have asupply of materials for the atostors."

  "They don't seem to do much good."

  "They're the best we've got. All the photocells on Earth and Venus andMercury are at present busy storing the sun's power in atostors. I havetwo thousand tons of charged mercury in our tanks here in the 'LunarBank.'"

  "Much good that will do--they can just pull and pull and pull till it'sall gone. A starfish isn't strong, but he can open the strongest oysterjust because he can pull from now on. You may have a lot of power--but."

  "But--we also have those new fifteen-foot UV beams. And one fifteen-footUV beam is worth, theoretically, nine five-foot beams, and practically,a dozen. We have a dozen of them. Remember, this place was designed notonly to protect itself, but Earth, too."

  "They can still pull, can't they?"

  "They'll stop pulling when they get their fingers burned. In themeantime, why not use some of those IP ships to bring in a few morecargoes of charged mercury?"

  "They aren't good for much else, are they? I wonder if those fellowshave anything more we don't know?"

  "Oh, probably. I'm going to work on that crumbler thing. That's thefirst conside
ration now."

  "Why?"

  "So we can move a ship. As it is, even those two we built aren't anygood."

  "Would they be anyway?"

  "Well--I think I might disturb those gentlemen slightly. Remember, theyeach have a nose-beam eighteen feet across. Exceedingly unpleasantcustomers."

  "Score: Strangers; magnetic field, atomic bombs, atomic power, crumblerray. Home team; UV beams."

  Kendall grinned. "I'd heard you were a pessimistic cuss when battlestarted--"

  "Pessimistic, hell, I'm merely counting things up."

  "McClellan had all the odds on Lee back in the Civil War of theStates--but Lee sent him home faster than he came."

  "But Lee lost in the end."

  "Why bring that up? I've got work to do." Still smiling, Kendall went tothe laboratory he had built up in the "Lunar Bank." Devin was alreadythere, calculating. He looked unhappy.

  "We can't do anything, as far as I can see. They're using an electricfield all right, and projecting it. I can't see how we can do that."

  "Neither can I," agreed Kendall, "so we can't use that weapon. I reallydidn't want to anyway. Like the neutron gun which I told CommanderMcLaurin would be useless as a weapon, they'd be prepared for it, youcan be sure. All I want to do is fight it, and make their projectionuseless."

  "Well, we have to know how they project it before we can break up theprojection, don't we?"

  "Not at all. They're using an electric field of very high frequency, butvariable frequency. As far as I can see, all we need is a similarvariable electric field of a slightly different frequency to heterodynetheirs into something quite harmless."

  "Oh," said Devin. "We could, couldn't we? But how are you going to dothat?"

  "We'll have to learn, that's all."

  * * * * *

  Buck Kendall started trying to learn. In the meantime, the Mirans weretaking over Jupiter. There were three IP stations on the planet itself,but they were vastly hindered by the thick, almost ultra-violet-proofatmosphere of Jupiter. Their rays were weak. And the magnetic fields ofthe Mirans were unaffected. Only their atomic bombs were hindered by theheavier gravity that pulled the rocks back in place faster than thebombs could throw them out. Still--a few hours of work, and the IPstations on Jupiter had rolled wildly across the flat plains of theplanet like dented cans, to end in utter destruction.

  The Mirans had paid no attention to the fleeing passenger and freighterships that left the planet, loaded to the utmost with human cargo, andabsolutely no freight. The IP fleet had to go to their rescue withoxygen tanks to take care of the extra humans, but nearly three-quartersof the population of Jupiter, a newly established population, and hencea readily mobile one, was saved. The others, the Mirans did not botherwith particularly except when they happened to be near where the Miranswanted to work. Then they were instantly destroyed by atomic bombing, orgamma rays.

  The Mirans settled almost at once, and began their work of finding onJupiter the badly needed atomic fuels. Machines were set up, and workbegun, Mirans laboring under the gravity of the heavy planet. Then,fifty ships swam up again, reloaded with fuel, and with crews consistingsolely of uninjured warriors, and started for Mars.

  Mars was half way between her near conjunction and her maximumelongation with respect to Jupiter at that time. The Mirans knew theirbusiness though, for they started in on the IP station on Phobos. Theywere practiced by this time, and this IP station had only sevenfive-foot beams. In half an hour that station fell, and its sisterstation on Deimos followed. Three wounded ships returned to Jupiter, andten new ships came out. The attack on Mars itself was started.

  Mars was a different proposition. There were thirty-two IP stationshere, one of them nearly as powerful as the Lunar Bank station. It wasequipped with four of the huge fifteen-foot beams. And it had fifteentons of mercury, more than seven-eighths charged. The Mars CenterStation was located a short ten miles from the Mars Center City, andunder the immediate orders of the IP heads, Mars Center City had beenvacated.

  For two days the Mirans hung off Mars, solidifying their positions onPhobos and Deimos. Then, with sixty-two ships, they attacked. They hadmade some very astute observations, and they started on the smallerstations just beyond the range of the Mars Center Station. Naturally,near so powerful a center, these stations had never been strong. Theyfell rapidly. But they had been counted on by Mars Center as auxiliarysupports. McLaurin had sent very definite orders to Mars Centerforbidding any action on their part, save gathering of power-supplies.

  At last the direct attack on Mars Center was launched. For the firsttime, the Mirans saw one of the fifteen-foot beams. Mars' atmosphere isthin, and there is little ozone. The ultra-violet beams were nearly aseffective as in empty space. When the Mirans dropped their ships, a fullthirty of them, into the circle formation, Mars Center answered at once.All four beams started.

  Those fifteen-foot beams, connected directly to huge atostor releaseapparatus, delivered a maximum power of two and three-quarter billionhorsepower, each. The first Miran ship struck, sparkled magnificently,and a terrific cascade of white-hot metal rolled down from its nose. Thegreat ship nosed down and to the left abruptly, accelerated swiftly--andcrashed with tremendous energy on the plain outside of Mars Center City.White, unwavering flames licked up suddenly, and made a column fivehundred feet high against the dark sky. Then the wreck exploded with aviolence that left a crater half a mile across.

  Three other ships had been struck, and were rapidly retreating. Anothertry was made for the ring formation, and four more ships were wounded,and replaced. The ring did not retreat, but the great magnetic fieldstarted. Atomic and gamma ray bombs started now, flashing sometimesdangerously close to the station as its magnetic field battled therotating field of the ships. The four greater beams, and many smallerones were in swift and angry action. Not more than a ten-second exposurecould be endured by any one ship, before it must retreat.

  * * * * *

  For five minutes the Mirans hung doggedly at their task. Then, wisely,they retreated. Of the fleet, not more than seven ships remaineduntouched. Mars Center Station had held--at what cost only they knew.Five hundred tons of their mercury had been exhausted in that brief fiveminutes. One hundred tons a minute had flowed into and out of theatostor apparatus. Mars Center radioed for help, when the fleet lifted.

  There was one other station on Mars that stood a good chance ofsurvival, Deenmor Station, with three of the big beams installed, andapparatus for their fourth was in the station, and being rapidly workedover. McLaurin did a wise and courageous thing, at which every man onMars cursed. He ordered that all IP stations save these two be deserted,and all mercury fuel reserves be moved to Deenmor and Mars Center.

  The Mirans could not land on the North Western section of Mars, nor inthe South Central region. Therefore Mars was not exactly habitable toMiran ships, because the great beams had been so perfectly figured thatthey were effective at a range of nearly twelve hundred miles.

  Deenmor station was attacked--but it was a half-hearted attack, forMirans were becoming distinctly skittish about fifteen-foot UV beams.Two badly blistered ships--and the Mirans retreated to Jupiter. But Miraheld Phobos and Deimos. In two weeks, they had set up cannon there, andproved themselves accurate long-range gunners. Against the feebleattraction of Deimos, and with Mars' gravity to help them, they beganbombarding the two stations, and anything that attempted to approachthem, with gamma and atomic explosive bombs. Meanwhile they amusedthemselves occasionally by planting a gamma-ray bomb in each of Mars'major cities. They made Mars uninhabitable for Solarians as well as forMirans, at least until the deadly slow-action atomic explosives woreoff, or were removed.

  Then the Mirans, after a lapse of three weeks while they dug in theirtoes on Jupiter, prepared to leap. Earth was the next goal. Miranscout-ships had been sent out before this--and severely handled by theconcentrated fleets of the IP that hung grimly off Earth and Luna now.But t
he scouts had learned one thing. Mirans could never hope to attaina firm grasp on Earth while terribly armed Luna hung like a Sword ofDamocles over their heads. Further, attack on Earth directly would benext to impossible, for, thanks to Faragaut's Interplanetary Company,nearly all the mercury metal in the system was safely lodged on Earth,and saturated with power. Every major city had been equipped with greatUV apparatus. And neutron guns in plenty waited on small ships justoutside the atmosphere to explode harmlessly any atomic or gamma bombsMiran ships might attempt to deposit.

  An attack on Luna was the first step. But that terrible, gigantic forton Luna worried them. Yet while that fort existed, Earth ships were freeto come and go, for Mirans could not afford to stand near. At a distanceof twenty thousand miles, small Miran ships had felt the touch of thosegreat UV beams.

  Finally, a brief test-attack was made, with an entire fleet of onehundred ships. They drew almost into position, faster than light, fasterthan the signaling warnings could send their messages. In position, allthose great ships strained and heaved at the mighty magnetic vortex thattwisted at the field of the fort. Instantly, twelve of the fifteen-footUV beams replied. And--two great UV beams of a size the Mirans had neverseen before, beams from the two ships, "S Doradus" and "Cepheid."

  The test-attack dissolved as suddenly as it had come. The Miransreturned to Jupiter, and to the outer planets where they had furtherestablished themselves. Most of the Solar system was theirs. But theSolarians still held the choicest planets--and kept the Mirans fromusing the mild-temperatured Mars.