"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.