The older man looked at me and said in French, which perhaps he thought I wouldn’t understand, “This is no place to bring a little one.”
Johann replied in German. “She asks many questions.” He shrugged, and said, “I wanted to show her.”
The other said, still in French, “She couldn’t understand.” Right then I resolved that I would make myself understand, whatever it was that they thought I could not. The man looked at me critically, taking in, no doubt, my straight black hair and almond eyes. “She’s not yours, anyway. What is she to you?”
“She is my daughter,” Johann said.
The molecular still was nothing to look at. It was a room filled with curtains of black velvet, doubled back and forth, thousands and thousands of meters of blackness. “Here it is,” Johann said. “Look well, little Leah, for in all the world, you will never see such another.”
Somewhere there was a fan that pushed air past the curtains; I could feel it on my face, cool, damp air moving sluggishly past. The floor of the room was covered with white dust, glistening in the darkness. I reached down to touch it, and Johann reached out to still my hand. “Not to touch,” he said.
“What is it?” I asked in wonder.
“Can’t you smell it?”
And I could smell it, in fact, I had been nearly holding my breath to avoid smelling it. The smell was thick, pungent, almost choking. It made my eyes water. “Ammonia,” I said.
Johann nodded, smiling. His eyes were bright. “Ammonium nitrate,” he said.
I was silent most of the way back to the fortified basement we shared with two other families. There must have been bombs, for there were always the birds, but I do not recall them. At last, just before we came to the river, I asked, “Why?”
“Oh, my little Leah, think. We are cut off here. Do we have electrical generators to run coilguns like the barbarians that surround us? We do not. What can we do, how can we defend ourselves? The molecular still sorts molecules out of the air. Nitrogen, oxygen, water; this is all that is needed to make explosives, if only we can combine them correctly. My molecular still takes the nitrogen out of the air, makes out of it ammonium nitrate, which we use to fire our cannons, to hold the barbarians away from our city.”
I thought about this. I knew about molecules by then, knew about nitrogen and oxygen, although not about explosives. Finally something occurred to me, and I asked, “But what about the energy? Where does the energy come from?”
Johann smiled, his face almost glowing with delight. “Ah, my little Leah, you know the right questions already. Yes, the energy. We have designed our still to work by using a series of reactions, each one using no more than a gnat’s whisker of energy. Nevertheless, you are right, we must needs steal energy from somewhere. We draw the thermal energy of the air. But old man entropy, he cannot be cheated so easily. To do this we need a heat sink.”
I didn’t know then enough to follow his words, so I merely repeated his words dumbly: “A heat sink?”
He waved his arm, encompassing the river, flowing dark beneath a thin sheet of ice. “And what a heat sink! The barbarians know we are manufacturing arms; we fire the proof of that back at them every day, but they do not know where! And here it is, right before them, the motive power for the greatest arms factory of all of Austria, and they cannot see it.”
Molecular still or not, the siege went on. The Pan-Slavics drove back the Tenth Crusade, and resumed their attack on the city. In February the armies entered the city twice, and twice the ragged defenders drove them back. In April, once more, the flowers bloomed, and once more, we had survived another winter.
It had been months since I had had a bath; there was no heat to waste on mere water, and in any case, there was no soap. Now, at last, we could wash, in water drawn directly from the Salzach, scrubbing and digging to get rid of the lice of winter.