White light lashed across them.

The flare caught them all by surprise. Charlie was one of the fortunate ones. He was facing away from the blast, and so he was not blinded at once. He saw the high cirrus starkly outlined, blue-white against the sullen, crimson Jemman sky, saw the shapes of the new flock picked out in brighter, sharper colors than he had ever seen. Minutes later he heard the sound, and behind him and below a new thundercloud boiled up out of the undercast.

Chorus of welcome became a dirge of pain and fear. Charlie could only reply with a lifting song. The seniors of the new flock took it up, and the swarm dropped ballast, belched swallowed hydrogen into their sacs, and rose. A few did not. They were not merely blind; they were in too great pain to respond.

Although they were far from the blast, when the winds struck, the swarm was thrown helter-skelter across the sky. Charlie had never felt such gusts before. Always in other storms there had been warning — gathering clouds and the deadly play of lightning to tell them it was time to swallow hydrogen and ride out the storm, or soar to escape above it. This time there was no warning and no escape. His feeding flaps and winglets felt as though they were being torn out at the roots. Captive of the huge sail of his surface, he was thrown through the new flock, caroming off their seniors, cannoning balloonets out of the way.

And then, without warning, he felt the familiar creeping tension of the surface of his gas sac and recognized the sweet, stinging odor of the females. Estrus, swarming time, time to breed!

The spinnerets of the females were working furiously now, spraying threadlike ova and pheronomes into the air. All around the swarm, the air was fragrant with the demand to breed. For Charlie, and for all the males, there was no question about what to do next: hive up, spray milt, soar back and forth through the stinging mist while their teats elongated, convulsed, spread their seed. The skins of their air sacs tightened, drawing the features of their tiny faces into caricatures. Behind the expressions that looked like pain was pain. The overtures to sex were no joy to Charlie. They were like being locked in an Iron Maiden with acid-tipped spikes. Only the relief that came when the semen squirted out made the pain end.

But it was wrong, wrong!

Charlie sang out his question and his fear, and the new flock sang with him. What breeding was this, with the flare coming from the enemy ground and not the sky? What was this heat that smote them like a fist, following on the thunder and the wild gales? Charlie could see that in the turbulence most of the silklings had been missed by the milt. They were all over the sky. Within his own body he could feel it was wrong. Where was the bubbling of hydrogen to replenish his sac, radiation-stung out of his body fluids? And what — what was this monstrous, bubbling cloud that was growing so fast it was drawing them all toward it?

And that was the question that answered all the others and put an end to questions forever for Charlie as the searing heat of the nuclear cloud burned out his eye patches, cracked his gas sac, touched off the hydrogen that spilled out, and ended his songs for always.

As NUCLEAR EXPLOSIONS went, it was inconsiderable. Less than a kiloton, it would hardly have been noticed in the multi-megaton blasts that had scoured the surface of Earth. When the imploding grenades forced the bright plutonium needles out of their sheaths to mate, they were in contact for only a few microseconds before their own immense reaction drove them apart.

But by then the explosion had occurred. The needles, the shell, the walls of the tunnel around them had been vaporized to a hot gas, billions of atmospheres of pressure, irresistibly determined to escape. It escaped. Within a few thousandths of a second it had formed its pipsqueak fireball, fifty meters across, racing upward at five hundred kilometers an hour, brighter than Kung, brighter than Earth’s sun, brighter than hundreds of them put together. The fireball grew and soared, first bright red with its burden of nitric acid, then whitening and losing its brightness as it began to cool.

Even through closed eyes that stark flare was visible to the people huddled in the cave, and the shock front that swept over them shook the cave and their bodies. The noise was immense. After it, over the echoes, Kris Kristianides was shouting, “Stay down! Don’t open your eyes! Wait!” For nearly ten minutes she kept them there, and then, slowly, she peered through half-closed lids and the dark goggles and announced they could get up.

Tentatively they poked their heads over the ridge. Squinting, they saw what Marge Menninger had done.

The nuclear cloud boiled tall through the layers of stratus. It had punched its own hole in the rain clouds, but its mushroom top was out of sight. Nearer, the Greasy camp seemed hardly touched: a shed blown over, a couple of tents burning, people moving dazedly around.

“She — she missed the base!” cried Kris, and Danny Dalehouse could not tell whether her tone was angry or glad. But what she said was true. The bottom of the blast was half a kilometer away from the camp toward the Heat Pole. Marge had got herself lost. The half of the blast that went into explosive pressure had wasted itself on the sand and succulents of the steppe.

But the third that went into heat had done better. The nearest persons in the Greasy camp were staggering around, blind and in agony. No one had given them goggles. No one had warned them not to look toward the blast.

“Check your pieces,” Kristianides ordered. She had taken the goggles off, and under them her eyes were red. But her voice was determined. “Put on your cloaks. Let’s go. We’re moving in.”

Dalehouse stood up and pulled the plastic poncho over his head like an automaton. (Would that really protect against any fallout at all?) He picked up his recoilless and slapped a cartridge into the breech. (Why am I doing this?) He started off with the others in a ragged line of skirmish, all nine of them walking slowly toward the Fuel base.

At every step he was telling himself that it was wrong. Wrong tactically: the nuclear blast had knocked out no more than a few unfortunates, and they were likely to get their heads blown off by the survivors. Wrong strategically: they should never have allowed themselves to get into this position. And wrong, most wrong of all, morally. What kind of world were they fighting for when they killed people without warning?

Dalehouse looked uneasily back and forth at the others in the line. All were staring straight ahead at the Fuel camp. Didn’t any of them feel the way he did?

He stopped in his tracks. “Kris,” he said, “I don’t want to do this.”

She turned slowly so that the muzzle of her gun covered him. “Move your ass, Dalehouse.”

“No, wait, Kris. Let’s—”

She said tightly, “I was expecting that from you. We’re going in there. All of us. Colonel Menninger set this up, and I’m not going to let it go to waste. Now move it.”

The others had stopped to look at them. None of them spoke; they only waited while Dalehouse watched the barrel of the GORR come into line with the bridge of his nose. He sighed deeply and said, “No, Kris.” And then he stood there as her expression changed and hardened and he realized that, yes, she was going to pull the trigger -

“Put down your rifle, lieutenant,” Ana called.

She was behind Kris and a little to one side, and she had her own gun pointed firmly at the lieutenant’s back. “I do not wish to kill,” she said, “but I, too, do not want to attack this camp.”

Dalehouse didn’t wait to see what would happen. He stepped forward and took the GORR from Kristianides’s hands. He threw it back over the crest of the hill they had just crossed and then followed it with his own. After a second Ana did the same, and so, one by one, did the others.