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 arsenal

by 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 project

electric fields. These projected fields are oscillated, and they are

tuned in with some parts of the ship. I suspect they are crystals of the

metals. If they can start a vibration in the crystals of the

metal--that's fatigue, metal fatigue enormously speeded. You know how a

quartz crystal oscillator in a radio-control apparatus will break, if

you work it on a very heavy load at the peak? They simply smash the

crystals of metal in the same way. Only they project their field."

"Then our toughest metals are useless? Can't something tough, rather

than hard, like copper or even silver for instance, stand it?"

"Calcium metal's the toughest going--and even that would break under the

beating those ships give it. The only way to withstand it is to have

such a mass of metal that the oscillations are damped out. But--"

The set tuned in on the IP station on Europa was speaking again. "The

ships are returning. There are one hundred and twenty-nine by accurate

count. Jorgsen reports that telescopic observation of the dead on the

fallen cruiser show them to be a _completely un-human race_! They are

of mottled coloring, predominately grayish brown. The ships are

returning. 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 is

descending within range, and we are focusing our beams on them--"

Out by Europa, ten great UV beams were stabbing angrily toward ten great

interstellar ships. The metal of the hulls glowed brilliant, and

distorted slowly as the thick walls softened under the heat, and the air

behind pressed against it. Grimly the ten ships came on. Torpedoes were

being launched, and exploded, and now they had no effect, for the Mirans

within were protected.

The eighteen grouped ships separated, and arranged themselves in a

circle around the fort. Suddenly one staggered as a great puff of gas

shot out through the thin atmosphere of Europa to flare brilliantly in

the lash of the stabbing UV beam. Instantly the ship righted itself, and

labored upward. Another dropped to take its place--

And the great walls of the IP fort suddenly groaned and started in their

welded joints. The faint, whispering rustle of the crumbling beam was

murmuring through the station. Engineers shouted suddenly as meters

leapt the length of their scales, and the needles clicked softly on the

stop pins. A thin rustle came from the atostors grouped in the great

power room. "Spirits of Space--a revolving magnetic field!" roared the

Chief Technician. "They're making this whole blasted station a squirrel

cage!"

The mighty walls of eight-foot metal shuddered and trembled. The UV

beams lashed out from the fort in quivering arcs now, they did not hold

their aim steady, and the magnetic shield that protected them from

atomic bombs was working and straining wildly. Eighteen great ships

quivered and tugged outside there now, straining with all their power to

remain in the same spot, as they passed on from one to another the

magnetic impulses that were now creating a titanic magnetic vortex about

the fort.

"The atostors will be exhausted in another fifteen minutes," the Chief

Technician roared into his transmitter. "Can the signals get through

those fields, Commander?"

"No, Mac. They've been stopped, Sparks tells me. We're here--and let's

hope we stay. What's happening?"

"They've got a revolving magnetic field out there that would spin a

minor planet. The whole blasted fort is acting like the squirrel cage in

an induction motor! They've made us the armature in a five hundred

million horsepower electric motor."

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

"I don't know--it was never--" The Chief stopped. Outside a terrific

roar and crash had built up. White darts of flame leapt a thousand feet

into the air, hurling terrific masses of shattered rock and soil.

"I was going to say," the Chief went on, "this place wasn't designed for

that sort of a strain. Our own magnetic field is supporting us now,

preventing their magnetic field from getting its teeth on metal. When

the strain comes--well, they're cutting loose our foundation with atomic

bombs!"

Five UV beams were combined on one interstellar ship. Instantly the

great machine retreated, and another dropped in to take its place while

the 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 the

power of one gives out, remember."

"What's our reserve now?"

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

minutes ago!"

Commander Wallace sent some other orders. Every torpedo tube of the

station suddenly belched forth deadly, fifteen-foot torpedoes, most of

them mud-torpedoes, torpedoes loaded with high explosive in the nose, a

delayed fuse, and a load of soft clinging mud in the rear. The mud would

flow down over the nose and offer a resistance foot-hold for the

explosive which empty space would not. Four hundred and three torpedoes,

equipped with anti-magnetic apparatus darted out. One hundred and four

passed the struggling fields. One found lodgement on a Miran ship, and

crushed in a metal wall, to be stopped by a bulkhead.

The Chief engineer watched his power declining. All ten UV beams were

united in one now, driving a terrible sword of energy that made the

attacked ship skip for safety instantly, yet the beams were all but

useless. For the Miran reserves filled the gap, and the magnetic tornado

continued.

For seventeen long minutes the station resisted the attack. Then the

last of the strained mercury flowed into the receivers, and the vast

power of the atostors was exhausted. Slowly the magnetic fields

declined. The great walls of the station felt the clutching lines of

force--they began to heat and to strain. A low, harsh grinding became

audible over the roar of the atomic bombs. The whole structure trembled,

and jumped slightly. The roar of bombs ceased suddenly, as the station

jerked again, more violently. Then it turned a bit, rolled clumsily.

Abruptly it began to spin violently, more and more rapidly. It started

rolling clumsily across the plateau--

A rain of atomic bombs struck the unprotected metal, and the eighth

breached the walls. The twentieth was the last. There was no longer an

IP station on Europa.

"The difference," said Buck Kendall slowly, when the reports came in

from scout-ships in space that had witnessed the last struggle, "between

an atomic generator and an atomic power-store, or accumulator, is

clearly shown. We haven't an adequate _source_ of power."