She calmed down, but her look remained troubled. "You're right, we are different," she said low. "Isolated, living and working under conditions we can hardly imagine on Earth--and you can't really imagine our problems--yes, you're becoming another people. I hope it will never go so far that--No. I don't want to think about it." She drained her gla.s.s and held it out for a refill, smiling. "Very well, sir, when do you next plan to be in Paris?"

An exceedingly enjoyable while later, the time came to go watch the _Pallas Castle_ maneuver in. In fact, it had somehow gotten past that time, and they were late; but they didn't hurry their walk aft. Blades took Ellen's hand; and she raised no objection. Schoolboyish, no doubt--however, he had reached the reluctant conclusion that for all his dishonorable intentions, this affair wasn't likely to go beyond the schoolboy stage. Not that he wouldn't keep trying.

As they glided through the refining and synthesizing section, which filled the broad half of the asteroid, the noise of pumps and regulators rose until it throbbed in their bones. Ellen gestured at one of the pipes which crossed the corridor overhead. "Do you really handle that big a volume at a time?" she asked above the racket.

"No," he said. "Didn't I explain before? The pipe's thick because it's so heavily armored."

"I'm glad you don't use that dreadful word 'cladded.' But why the armor? High pressure?"

"Partly. Also, there's an inertrans lining. Jupiter gas is h.e.l.lishly reactive at room temperature. The metallic complexes especially; but think what a witch's brew the stuff is in every respect. Once it's been refined, of course, we have less trouble. That particular pipe is carrying it raw."

They left the noise behind and pa.s.sed on to the approach control dome at the receptor end. The two men on duty glanced up and immediately went back to their instruments. Radio voices were staccato in the air.

Blades led Ellen to an observation port.

She drew a sharp breath. Outside, the broken ground fell away to s.p.a.ce and the stars. The ovoid that was the ship hung against them, lit by the hidden sun, a giant even at her distance but dwarfed by the balloon she towed. As that bubble tried ponderously to rotate, rainbow gleams ran across it, hiding and then revealing the constellations.

Here, on the asteroid's axis, there was no weight, and one moved with underwater smoothness, as if disembodied. "Oh, a fairy tale," Ellen sighed.

Four sparks flashed out of the boat blisters along the ship's hull.

"Scoopships," Blades told her. "They haul the cargo in, being so much more maneuverable. Actually, though, the mother vessel is going to park her load in orbit, while those boys bring in another one ... see, there it comes into sight. We still haven't got the capacity to keep up with our deliveries."

"How many are there? Scoopships, that is."

"Twenty, but you don't need more than four for this job. They've got terrific power. Have to, if they're to dive from orbit down into the Jovian atmosphere, ram themselves full of gas, and come back. There they go."

The _Pallas Castle_ was wrestling the great sphere she had hauled from Jupiter into a stable path computed by Central Control. Meanwhile the scoopships, small only by comparison with her, locked onto the other balloon as it drifted close. Energy poured into their drive fields.

Spiraling downward, transparent globe and four laboring s.p.a.cecraft vanished behind the horizon. The _Pallas_ completed her own task, disengaged her towbars, and dropped from view, headed for the dock.

The second balloon rose again, like a huge gla.s.s moon on the opposite side of the Sword. Still it grew in Ellen's eyes, kilometer by kilometer of approach. So much ma.s.s wasn't easily handled, but the braking curve looked disdainfully smooth. Presently she could make out the scoopships in detail, elongated teardrops with the intake gates yawning in the blunt forward end, c.o.c.kpit canopies raised very slightly above.

Instructions rattled from the men in the dome. The balloon veered clumsily toward the one free receptor. A derricklike structure released one end of a cable, which streamed skyward. Things that Ellen couldn't quite follow in this tricky light were done by the four tugs, mechanisms of their own extended to make their tow fast to the cable.

They did not cast loose at once, but continued to drag a little, easing the impact of centrifugal force. Nonetheless a slight shudder went through the dome as slack was taken up. Then the job was over.

The scoopships let go and flitted off to join their mother vessel. The balloon was winched inward. s.p.a.cesuited men moved close, preparing to couple valves together.

"And eventually," Blades said into the abrupt quietness, "that cargo will become food, fabric, vitryl, plastiboard, reagents, fuels, a hundred different things. That's what we're here for."

"I've never seen anything so wonderful," Ellen said raptly. He laid an arm around her waist.

The intercom chose that precise moment to blare: "Attention!

Emergency! All hands to emergency stations! Blades, get to Chung's office on the double! All hands to emergency stations!"

Blades was running before the siren had begun to howl.

Rear Admiral Barclay Hulse had come in person. He stood as if on parade, towering over Chung. The asterite was red with fury. Avis Page crouched in a corner, her eyes terrified.

Blades barreled through the doorway and stopped hardly short of a collision. "What's the matter?" he puffed.

"Plenty!" Chung snarled. "These incredible thumble-fumbed oafs--" His voice broke. _When he gets mad, it means something!_

Hulse nailed Blades with a glance. "Good day, sir," he clipped. "I have had to report a regrettable accident which will require you to evacuate the Station. Temporarily, I hope."

"Huh?"

"As I told Mr. Chung and Miss Page, a nuclear missile has escaped us.

If it explodes, the radiation will be lethal, even in the heart of the asteroid."

"What ... what--" Blades could only gobble at him.

"Fortunately, the _Pallas Castle_ is here. She can take your whole complement aboard and move to a safe distance while we search for the object."

"How the _devil_?"

Hulse allowed himself a look of exasperation. "Evidently I'll have to repeat myself to you. Very well. You know we have had to make some adjustments on our launchers. What you did not know was the reason.

Under the circ.u.mstances, I think it's permissible to tell you that several of them have a new and secret, experimental control system.

One of our missions on this cruise was to carry out field tests. Well, it turned out that the system is still full of, ah, bugs. Gunnery Command has had endless trouble with it, has had to keep tinkering the whole way from Earth.

"Half an hour ago, while Commander Warburton was completing a rea.s.sembly--lower ranks aren't allowed in the test turrets--something happened. I can't tell you my guess as to what, but if you want to imagine that a relay got stuck, that will do for practical purposes. A missile was released under power. Not a dummy--the real thing. And release automatically arms the war head."

The news was like a hammerblow. Blades spoke an obscenity. Sweat sprang forth under his arms and trickled down his ribs.

"No such thing was expected," Hulse went on. "It's an utter disaster, and the designers of the system aren't likely to get any more contracts. But as matters were, no radar fix was gotten on it, and it was soon too far away for gyrogravitic pulse detection. The thrust vector is unknown. It could be almost anywhere now.

"Well, naval missiles are programmed to reverse acceleration if they haven't made a target within a given time. This one should be back in less than six hours. If it first detects our ship, everything is all right. It has optical recognition circuits that identify any North American warcraft by type, disarm the war head, and steer it home.

But, if it first comes within fifty kilometers of some other ma.s.s--like this asteroid or one of the companion rocks--it will detonate. We'll make every effort to intercept, but s.p.a.ce is big.

You'll have to take your people to a safe distance. They can come back even after a blast, of course. There's no concussion in vacuum, and the fireball won't reach here. It's princ.i.p.ally an anti-personnel weapon. But you must not be within the lethal radius of radiation."

"The h.e.l.l we can come back!" Avis cried.

[Ill.u.s.tration]

"I beg your pardon?" Hulse said.

"You imbecile! Don't you know Central Control here is cryotronic?"

Hulse did not flicker an eyelid. "So it is," he said expressionlessly.

"I had forgotten."

Blades mastered his own shock enough to grate: "Well, we sure haven't.

If that thing goes off, the gamma burst will kick up so many minority carriers in the transistors that the _p_-type crystals will act _n_-type, and the _n_-type act _p_-type, for a whole couple of microseconds. Every one of 'em will flip simultaneously! The computers' memory and program data systems will be scrambled beyond hope of reorganization."

"Magnetic pulse, too," Chung said. "The fireball plasma will be full of inh.o.m.ogeneities moving at several per cent of light speed. Their electromagnetic output, hitting our magnetic core units, will turn them from super to ordinary conduction. Same effect, total computer amnesia. We haven't got enough shielding against it. Your TIMM systems can take that kind of a beating. Ours can't!"