“Blowing them open? I thought you were cutting them off.”

“We were, but then Tabbi figured out how to pack a small charge that cracked them apart on the line of the vacuum fuse. About half the time they’re reusable. The other half they’re no more ruined than if we’d cut “em.” Agba looked quite proud of himself.

“You haven’t used it all for that, surely!”

“Well, there was a little spillage. Outside, of course,” Agba, misapprehending, added in response to Leo’s horrified look. He held out a sealed half-liter flask to Leo’s inspection. “This is the last of it. I figure it will just about finish the job.”

“Nng!” Leo’s snatching hands closed around the bottle and clutched it to his stomach like a man smothering a grenade. “I need that! I have to have it!” I have to have ten times that much! his thought howled silently.

“Oh,” said Agba. “Sorry.” He gave Leo a look of limpid innocence. “Does this mean we have to go back to cutting clamps?”

“Yes,” squeaked Leo. “Go,” he added. Yes, before he exploded himself.

Agba, with an uncertain smile, ducked back out the airlock. It sealed, leaving Leo alone a moment to hyperventilate in peace.

Think, man, think, Leo told himself. Don’t panic. There was something, some elusive fact or factor in the back of his mind, trying to tell him this wasn’t the end, but he could not at present recall… Unfortunately, a careful mental review of his calculations, keeping track on his fingers (oh, to be a quaddie!) only confirmed his initial fear.

The explosive fabrication of the titanium blank into the complex shape of the vortex mirror required, besides an assortment of spacers, rings, and clamps, three main parts; the ice die, the metal blank, and the explosive to marry the two. Shotgun wedding indeed. And what is the most important leg of a three-legged stool? The one that is missing, of course. And he’d thought the slurry explosive was going to be the easy part…

Forlorn, Leo began systematically going around the Toxic Stores module, checking its contents. An extra flask of slurry explosive might have been misplaced somewhere. Alas, the quaddies were all too conscientious in their inventory control. Each bin contained only what its label proclaimed, no more, no less. Agba had even updated the label on the bin just now; Contents, Slurry Explosive Type B-2, one-half liter flasks. Quantity, 0.

About this time Leo stumbled, literally, over a barrel of gasoline. No, some six barrels of the damn stuff, which had somehow washed up here, now strapped firmly to the walls. God knew where the rest of the hundred tons had gone. Leo wished it all in Hell, where it might at least be of some conceivable use. He would gladly trade the whole hundred tons of it for four aspirins. A hundred tons of gasoline, of which—

Leo blinked, and let out an “aaah” of exultation.

Of which a liter or so, mixed with tetranitro methane, would make an even more powerful explosive.

He would have to look it up, to be sure—he would have to look up the exact proportions in any case—but he was certain he had remembered aright. Learning and inspiration, that was the best combination of all. Tetranitro methane was used as an emergency oxygen source in several Habitat and pusher systems. It yielded more O2 per cc than liquid oxygen, without the temperature and pressure problems of storage, in a highly refined version of the early tetranitro methane candles which, when burned, gave off oxygen. Now—oh, God—if only the TNM hadn’t all been used by somebody, to—to blow up balloons for quaddie children or some damn thing—they had been losing air during the Habitat reconfiguration… Pausing only to put the flask back in its bin and arrange a sign on the barrels reading, in large red print, THIS IS LEO GRAF’S GASOLINE. IF ANYONE ELSE TOUCHES IT HE WILL BREAK ALL THEIR ARMS, he raced out of the Toxic Stores module and away to find the nearest working library computer terminal.

Twilight lingered on the dry lake bed, the luminous bowl of the sky darkening gradually through a deep turquoise to a star-flecked indigo. Silver found her attention constantly distracted from horizon-scan by the entrancing color changes of the planetary atmosphere seen through the ports. What subtle variety downsiders enjoyed: bands of purple, orange, lemon, green, blue, with cobalt feathers of water vapor melting in the western sky. It was with some regret that Silver switched the scan to infra-red. Its computer-enhanced colors gave clarity to her vision, but seemed crude and garish after the real thing.

At last came the sight her heart desired: a land rover, bouncing over the distant hilly pass and skidding down the last rocky slopes, then peeling out over the lake bed at maximum acceleration. Madame Minchenko hurried out of the pilot’s compartment to let down the hatch stairs as the land rover roared to a halt beside the shuttle.

Silver clapped all her hands with delight as she saw Ti thump up the ramp, burdened with Tony clinging piggy-back just as Leo had carted her at the Transfer Station. They got him! They got him! Dr. Minchenko followed close behind.

There was a short argument back at the airlock, Doctor and Madame Minchenko’s muffled voices, then Dr. Minchenko galloped back down the stairs to crack a cold flare and stick it to the land rover’s roof. It gave off a brilliant green glare. Good, the stranded security guards should have no trouble seeing that beacon, Silver decided with some relief.

Silver scrambled back across to the co-pilot’s seat as Ti staggered into the pilot’s compartment, dumped Tony into the engineer’s seat, and vaulted into the command chair. He yanked his breath mask down around his neck with one hand while switching on controls with the other. “Hey, who’s been messing with my ship…?”

Silver turned and pulled herself up to look over the top of her seat at Tony, who had rid himself of his own breath mask and was trying to get his seat straps in order. “You made it!” she grinned.

He grinned back. “ ‘ust bar-ry. ‘Er right behin’ us.” His blue eyes, Silver realized, were huge with pain as well as excitement, his lips swollen.

“What happened to you—?” Silver turned to Ti. “What happened to Tony?”

“That shit Van Atta burned him in the mouth with his damn cattle prod, or whatever the hell that thing was he had,” said Ti grimly, his hands dancing over the controls. The engines came alive, lights flickered, and the shuttle began to roll. Ti hit his intercom. “Dr. Minchenko? You folks strapped down back there yet?”

“Just a moment—” came Dr. Minchenko’s reply. “There. Yes, go!”

“Did you have any trouble?” asked Silver, sliding back into her seat and groping for her own straps as the shuttle taxied. “Not at first. We got to the hospital all right, walked right in with no problem. I thought sure the nurses were going to question our taking Tony, but evidently they all think Minchenko is God, there. We just blasted right through and were on our way out, with me playing donkey—that’s all I am, just transportation, y’know?—when who should we meet, going out the door, but that son-of-a-bitch Van Atta coming in.”

Silver gasped.

“We tripped him up—Dr. Minchenko wanted to stop and beat the shit out of him, on account of Tony’s mouth, but he would have had to delegate the most of it to me—he is an old man, little though he wants to admit it—I dragged him out to the land rover. I last heard Van Atta running off screaming for a security jetcopter. He’s surely found one by now…” Ti scanned the monitors nervously. “Yes. Damn. There,” he pointed. A colorized flare swooped over the mountains, marking the following ‘copter’s position in the monitor. “Well, they can’t catch us now.”