"What?"

"No more radio contact."

"Why?"

"Off, Ricky."

I dropped down on my knees behind a cardboard carton of supplies in the main room. The carton wasn't large enough to hide me entirely-my feet stuck out-but like Mae, I wasn't easily seen. Someone outside would have to look at an angle through the north window to see me. In any case, it was the best I could do.

From my crouched position, I could just see the others huddled beneath the sink. I couldn't see Mae at all, unless I really stuck my head around the corner of the carton. When I did, she looked quiet, composed. I ducked back and waited.

I heard nothing but the hum of the air conditioner.

Ten or fifteen seconds passed. I could see the sunlight streaming in through the north window above the sink. It made a white rectangle on the floor to my left. My headset crackled. "Why no contact?"

"Jesus fucking A," Charley muttered.

I put my finger to my lips, and shook my head.

"Ricky," I said, "don't these things have auditory capacity?"

"Sure, maybe a little, but-"

"Be quiet and stay off."

"But-"

I reached for the transmitter at my belt, and clicked it off. I signaled the others beneath the sink. They each turned their transmitters off.

Charley mouthed something to me. I thought he mouthed, "That fucking guy wants us killed."

But I couldn't be sure.

We waited.

It couldn't have been more than two or three minutes, but it seemed forever. My knees began to hurt on the hard concrete floor. Trying to get more comfortable, I shifted my position cautiously; by now I was sure the first swarm was in our vicinity. It hadn't appeared at the windows yet, and I wondered what was taking so long. Perhaps as it followed our path it had paused to inspect the cars. I wondered what swarm intelligence would make of an automobile. How puzzling it must look to that high-resolution eye. But maybe because the cars were inanimate, the swarm would ignore them as some sort of large, brightly colored boulders. But still ... What was taking so long?

My knees hurt more with every passing second. I changed my position, putting weight on my hands and raising my knees like a runner at the blocks. I had a moment of temporary relief. I was so focused on my pain that I didn't notice at first that the glaring white rectangle on the floor was turning darker at the center, and spreading out to the sides. In a moment the entire rectangle turned dull gray.

The swarm was here.

I wasn't certain, but I fancied that beneath the hum of the air conditioner was a deep thrumming sound. From my position behind the crate, I saw the window above the sink grow progressively darker from swirling black particles. It was as if there was a dust storm right outside. Inside the shed it was dark. Surprisingly dark.

Underneath the sink, David Brooks began to moan. Charley clapped his hand over his mouth. They looked upward, even though the sink blocked their view of the window above them. And then the swarm vanished from the window, as quickly as it had come. Sunlight poured in again.

Nobody moved.

We waited.

Moments later, the window in the west wall turned dark, in the same way. I wondered why the swarm didn't enter. The window wasn't airtight. The nanoparticles could slide through the cracks without difficulty. But they didn't even seem to try. Perhaps this was an instance where network learning was on our side. Perhaps the swarms had been trained by their experience at the lab to think doors and windows were impermeable. Maybe that's why they weren't trying.

The thought gave me a hopeful feeling that helped counteract the pain in my knees. The west window was still dark, when the north window over the sink turned dark again. Now two swarms were looking in at the same time. Ricky had said there were three coming toward the building. He hadn't mentioned the fourth. I wondered where the third swarm was. A moment later, I knew.

Like a silent black mist, nanoparticles began to come into the room underneath the west door. Soon more particles entered, all around the door frame. Inside the room, the particles appeared to spin and swirl aimlessly, but I knew they would self-organize in a few moments. Then at the north window, I saw more particles flooding through the cracks. Through the air-conditioning vents in the ceiling, still more particles rushed downward. There was no point in waiting any longer. I got to my feet and stepped from my hiding place. I shouted for everybody to come out of hiding. "Form up in two rows!" Charley grabbed the Windex spray bottle and fell into line, grumbling, "What do you think our fucking chances are?"

"The best they'll ever get," I said. "Reynolds rules! Form up and stay with me! Let's go-now!"

If we weren't so frightened, we might have felt ridiculous, shuffling back and forth across the room in a tight cluster, trying to coordinate our movements-trying to imitate a flock of birds. My heart was pounding in my chest. I heard a roaring sound in my ears. It was hard to focus on our steps. I knew we were awkward, but we got better quickly. When we came to a wall, we wheeled and headed back again, moving in unison. I started swinging my arms and clapping with each step. The others did the same. It helped our coordination. And we each fought our terror. As Mae said later, "It was step aerobics from hell." And all the time, we watched the black nanoparticles as they came hissing into the room through cracks in doors and windows. It seemed to go on for a long time, but it was probably only thirty or forty seconds. Soon a kind of undifferentiated fog filled the room. I felt pinpricks all over my body, and I was sure the others felt it, too. David started moaning again, but Rosie was right beside him, encouraging him, urging him to keep it together. Suddenly, with shocking speed the fog cleared, the particles coalescing into two fully formed columns that now stood directly before us, rising and falling in dark ripples. Seen this close, the swarms exuded an unmistakable sense of menace, almost malevolence. Their deep thrumming sound was clearly audible, but intermittently I heard an angry hiss, like a snake.

But they did not attack us. Just as I had hoped, the programming deficits worked for us. Confronted by a cluster of coordinated prey, these predators were stymied. They did nothing at all.

At least for now.

Between claps, Charley said, "Do you believe-this fucking shit-it's working!" I said, "Yes but maybe-not for long." I was worried about how long David could control his anxiety. And I was worried about the swarms. I didn't know how long they'd just stand there before they innovated new behavior. I said, "I suggest we-move toward that-back door behind us-and get the hell out."

As we wheeled away from the wall, I angled slightly toward the rear room. Clapping and stepping in unison, our group moved away from the swarms, which thrummed deeply and followed.

"And if we get outside, then what?" David whined. He was having trouble staying in sync with the rest of us. In his panic, he kept stumbling. He was sweating and blinking rapidly. "We continue this way-flocking this way-back to the lab-and get inside-are you willing to try?"

"Oh jeez," he moaned. "It's so far ... I don't know if ..." He stumbled again, nearly lost his balance. And he wasn't clapping with the rest of us. I could almost feel his terror, his overwhelming urge to flee.

"David you stay with us-if you go on your own-you'll never make it-are you listening?" David moaned, "I don't know ... Jack ... I don't know if I can ..." He stumbled again, bumped into Rosie, who fell against Charley, who caught her and pulled her back to her feet. But our flock was knocked into momentary disarray, our coordination gone. Immediately, the swarms turned dense black, coiled and tightened, as if ready to spring. I heard Charley whisper "Oh fuck," under his breath, and indeed, for a moment I thought he was right, and that it was all over.

But then we regained our rhythm, and immediately the swarms rose up, returned to normal. Their dense blackness faded. They resumed their steady pulsing. They followed us into the next room. But still they did not attack. We were now about twenty feet from the back door, the same door we had come in. I started to feel optimistic. For the first time, I thought it was possible we really might make it.

And then, in an instant, everything went to hell.

* * *

David Brooks bolted.

We were well into the back room, and about to work our way around the freestanding shelves in the center of the room, when he ran straight between the swarms and past them, heading for the far door.

The swarms instantly spun and chased him.

Rosie was screaming for him to come back, but David was focused on the door. The swarms pursued him with surprising speed. David had almost reached the door-his hand was reaching for the doorknob-when one swarm sank low, and spread itself across the floor ahead of him, turning it black.

The moment David Brooks reached the black surface, his feet shot out from under him, as if he had stepped on ice. He howled in pain as he slammed onto the concrete, and immediately tried to scramble to his feet again, but he couldn't get up; he kept slipping and falling, again and again. His eyeglasses shattered; the frames cut his nose. His lips were coated with swirling black residue. He started to have trouble breathing.

Rosie was still screaming as the second swarm descended on David, and the black spread across his face, onto his eyes, into his hair. His movements became increasingly frantic, he moaned pitifully like an animal, yet somehow, as he slid and tumbled on hands and knees, he managed to make his way toward the door. At last he lunged upward, grabbed the doorknob, and managed to pull himself to his knees. With a final desperate movement, he twisted the knob, and kicked the door open as he fell.

Hot sunlight flared into the shed-and the third swarm swirled in from outside.

Rosie cried, "We've got to do something!" I grabbed her arm as she ran past me toward David. She struggled in my grip. "We have to help him! We have to help him!"

"There's nothing we can do."

"We have to help him!"

"Rosie. There's nothing we can do."

David was now rolling on the ground, black from head to toe. The third swarm had enveloped him. It was difficult to see through the dancing particles. It looked as though David's mouth was a dark hole, his eyeballs completely black. I thought he might be blind. His breath came in ragged gasps, with little choking sounds. The swarm was flowing into his mouth like a black river.

His body began to shudder. He clutched at his neck. His feet drummed on the floor. I was sure he was dying.

"Come on, Jack," Charley said. "Let's get the fuck out of here."

"You can't leave him!" Rosie shouted. "You can't, you can't!" David was sliding out the door, into the sunlight. His movements were less vigorous now; his mouth was moving, but we heard only gasps.

Rosie struggled to get free.

Charley grabbed her shoulder and said, "God damn it, Rosie-"

"Fuck you!" She wrenched free from his grip, she stamped on my foot and in my moment of surprise I let go, and she sprinted across the shed into the next room, shouting "David! David!" His hand, black as a miner's, stretched toward her. She grabbed his wrist. And in the same moment she fell, slipping on the black floor just as he had done. She kept saying his name, until she began to cough, and a black rim appeared on her lips.

Charley said, "Let's go, for Christ's sake. I can't watch."

I felt unable to move my feet, unable to leave. I turned to Mae. Tears were running down her cheeks. She said: "Go."

Rosie was still calling out David's name as she hugged him, pulled his body to her chest. But he didn't seem to be moving on his own anymore.

Charley leaned close to me and said, "It's not your fucking fault."

I nodded slowly. I knew what he was saying was true.

"Hell, this is your first day on the job." Charley reached down to my belt, flicked my headset on. "Let's go."

I turned toward the door behind me.

And we went outside.

DAY 6

4:12 P.M.

Beneath the corrugated roof, the air was hot and still. The line of cars stretched away from us. I heard the whirr of a video camera motor up by the roof. Ricky must have seen us coming out on the monitors. Static hissed in my headset. Ricky said, "What the hell's going on?"

"Nothing good," I said. Beyond the line of shade, the afternoon sun was still bright.

"Where are the others?" Ricky said. "Is everybody okay?"

"No. Everybody is not."

"Well tell me-"

"Not now." In retrospect, we were all numb from what had happened. We didn't have any reaction except to try and get to safety.

The lab building stood across the desert a hundred yards to our right. We could reach the power station door in thirty or forty seconds. We set off toward it at a brisk jog. Ricky was still talking, but we didn't answer him. We were all thinking about the same thing: in another half a minute we would reach the door, and safety.

But we had forgotten the fourth swarm.

"Oh fuck," Charley said.

The fourth swarm swirled out from the side of the lab building, and started straight toward us. We stopped, confused. "What do we do?" Mae said, "Flock?"

"No." I shook my head. "There's only three of us." We were too small a group to confuse a predator. But I couldn't think of any other strategy to try. All the predator-prey studies I had ever read began to play back in my head. Those studies agreed on one thing. Whether you modeled warrior ants or Serengeti lions, the studies confirmed one major dynamic: left to their own devices, predators would kill all the prey until none remained-unless there was a prey refuge. In real life the prey refuge might be a nest in a tree, or an underground den, or a deep pool in a river. If the prey had a refuge, they'd survive. Without a refuge, the predators would kill them all.

"I think we're fucked," Charley said.

We needed a refuge. The swarm was bearing down on us. I could almost feel the pinpricks on my skin, and taste the dry ashen taste in my mouth. We had to find some kind of shelter before the swarm reached us. I turned full circle, looking in all directions, but there was nothing I could see, except-

"Are the cars locked?"

My headset crackled. "No, they shouldn't be."

We turned and ran.

The nearest car was a blue Ford sedan. I opened the driver's door, and Mae opened the passenger side. The swarm was right behind us. I could hear the thrumming sound as I slammed the door shut, as Mae slammed hers. Charley, still holding the Windex spray, was trying to open the rear passenger door, but it was locked. Mae twisted in the seat to unlock the door, but Charley had already turned to the next car, a Land Cruiser, and climbed inside. And slammed the door.

"Yow!" he said. "Fucking hot!"

"I know," I said. The inside of the car was like an oven. Mae and I were both sweating. The swarm rushed toward us, and swirled over the front windshield, pulsating, shifting back and forth.

Over the headset, a panicked Ricky said, "Guys? Where are you? Guys?"

"We're in the cars."

"Which cars?"

"What fucking difference does it make?" Charley said. "We're in two of the fucking cars, Ricky."

The black swarm moved away from our sedan over to the Toyota. We watched as it slid from one window to another, trying to get in. Charley grinned at me through the glass. "It's not like the shed. These cars are airtight. So ... fuck 'em."

"What about the air vents?" I said.

"I shut mine."

"But they aren't airtight, are they?"

"No," he said. "But you'd have to go under the hood to begin to get in. Or maybe through the trunk. And I'm betting this overbred buzzball can't figure that out." Inside our car, Mae was snapping closed the dashboard air ducts one after another. She opened the glove compartment, glanced inside, shut it again. I said, "You find any keys?"

She shook her head, no.

Over the headset, Ricky said, "Guys? You got more company."

I turned to see two additional swarms coming around the shed. They immediately swirled over our car, front and back. I felt like we were in a dust storm. I looked at Mae. She was sitting very still, stony-faced, just watching.

The two new clouds finished circling the car, then came to the front. One was positioned just outside Mae's passenger door window. It pulsed, glinting silver. The other was on the hood of the car, moving back and forth from Mae to me. From time to time, it would rush the windshield, and disperse itself over the glass. Then it would coalesce again, back away down the hood, and rush again.

Charley cackled gleefully. "Trying to get in. I told you: they can't do it." I wasn't so sure. I noticed that with each charge, the swarm would move farther back down the hood, taking a longer run. Soon it would back itself up to the front grill. And if it started inspecting the grill, it could find the opening to the air vents. And then it would be over. Mae was rummaging in the utility compartment between the seats. She came up with a roll of tape and a box of plastic sandwich baggies. She said, "Maybe we can tape the vents ..." I shook my head. "There's no point," I said. "They're nanoparticles. They're small enough to pass right through a membrane."

"You mean they'd come through the plastic?"

"Or around, through small cracks. You can't seal it well enough to keep them out."

"Then we just sit here?"

"Basically, yes."

"And hope they don't figure it out."

I nodded. "That's right."

Over the headset, Bobby Lembeck said, "Wind's starting to pick up again. Six knots." It sounded like he was trying to be encouraging, but six knots wasn't anywhere near enough force. The swarms outside the windshield moved effortlessly around the car. Charley said, "Jack? I just lost my buzzball. Where is it?"

I looked over at Charley's car, and saw that the third swarm had slid down to the front tire well, where it was swirling in circles and moving in and out through the holes in the hubcap. "Checking your hubcaps, Charley," I said.

"Umm." He sounded unhappy, and with good reason. If the swarm started exploring the car thoroughly, it might stumble on a way in. He said, "I guess the question is, how big is their SO component, really?"

"That's right," I said.

Mae said, "In English?"

I explained. The swarms had no leader, and no central intelligence. Their intelligence was the sum of the individual particles. Those particles self-organized into a swarm, and their self-organizing tendency had unpredictable results. You really didn't know what they would do. The swarms might continue to be ineffective, as they were now. They might come upon the solution by chance. Or they might start searching in an organized way. But they hadn't done that so far.

My clothes were heavy, soaked in sweat. Sweat was dripping from my nose and chin. I wiped my forehead with the back of my arm. I looked at Mae. She was sweating, too. Ricky said, "Hey, Jack?"

"What."

"Julia called a while ago. She's checked out of the hospital and-"

"Not now, Ricky."

"She's coming out here tonight."

"We'll talk later, Ricky."

"I just thought you'd want to know."

"Jesus," Charley said, exploding. "Someone tell this asshole to shut up. We're busy!"

Bobby Lembeck said, "Eight knots of wind now. No, sorry ... seven."

Charley said, "Jesus, the suspense is killing me. Where's my swarm now, Jack?"

"Under the car. I can't see what it's doing ... No, wait ... It's coming up behind you, Charley. Looks like it's checking out your taillights."

"Some kind of car freak," he said. "Well, it can check away."

I was looking over my shoulder at Charley's swarm when Mae said, "Jack. Look." The swarm outside her window on the passenger side had changed. It was almost entirely silver now, shimmering but pretty stable, and on this silver surface I saw Mae's head and shoulders reflected back. The reflection wasn't perfect, because her eyes and mouth were slightly blurred, but basically it was accurate.

I frowned. "It's a mirror ..."

"No," she said. "It's not." She turned away from the window to look at me. Her image on the silver surface did not change. The face continued to stare into the car. Then, after a moment or two, the image shivered, dissolved and re-formed to show the back of her head. "What does that mean?" Mae said.

"I've got a pretty good idea, but-"

The swarm on the front hood was doing the same thing, except that its silver surface showed the two of us sitting side by side in the car, looking very frightened. Again, the image was somewhat blurred. And now it was clear to me that the swarm was not a literal mirror. The swarm itself was generating the image by the precise positioning of individual particles, which meant-

"Bad news," Charley said.

"I know," I said. "They're innovating."

"What do you figure, is it one of the presets?"

"Basically, yes. I assume it's imitation."

Mae shook her head, not understanding.

"The program presets certain strategies to help attain goals. The strategies model what real predators do. So one preset strategy is to freeze where you are and wait, to ambush. Another is to random-walk until you stumble on your prey, and then pursue. A third is to camouflage yourself by taking on some element of the environment, so you blend in. And a fourth is to mimic the prey's behavior-to imitate it."

She said, "You think this is imitation?"

"I think this is a form of imitation, yes."

"It's trying to make itself appear like us?"

"Yes."

"This is emergent behavior? It's evolved on its own?"

"Yes," I said.

"Bad news," Charley said mournfully. "Bad, bad news."

Sitting in the car, I started to get angry. Because what the mirror imaging meant to me was that I didn't know the real structure of the nanoparticles. I'd been told there was a piezo wafer that would reflect light. So it wasn't surprising that the swarm occasionally flashed silver in the sun. That didn't call for sophisticated orientation of the particles. In fact, you would expect that sort of silvery ripple as a random effect, just the way heavily trafficked highways will clog up and then flow freely again. The congestion was caused by random speed changes from one or two motorists, but the effect rippled down the entire highway. The same would be true of the swarms. A chance effect would pass like a wave down the swarm. And that's what we had seen.

But this mirroring behavior was something entirely different. The swarms were now producing images in color, and holding them fairly stable. Such complexity wasn't possible from the simple nanoparticle I'd been shown. I doubted you could generate a full spectrum from a silver layer. It was theoretically possible that the silver could be precisely tilted to produce prismatic colors, but that implied enormous sophistication of movement.

It was more logical to imagine that the particles had another method to create colors. And that meant I hadn't been told the truth about the particles, either. Ricky had lied to me yet again. So I was angry.

I had already concluded something was wrong with Ricky, and in retrospect, the problem lay with me, not him. Even after the debacle in the storage shed, I still failed to grasp that the swarms were evolving faster than our ability to keep pace with them. I should have realized what I was up against when the swarms demonstrated a new strategy-making the floor slippery to disable their prey, and to move them. Among ants, that would be called collective transport; the phenomenon was well known. But for these swarms, it was unprecedented, newly evolved behavior. Yet at the time I was too horrified to recognize its true significance. Now, sitting in the hot car, it wasn't useful to blame Ricky, but I was scared, and tired, and I wasn't thinking clearly.

"Jack." Mae nudged my shoulder, and pointed to Charley's car.

Her face was grim.

The swarm by the taillight of Charley's car was now a black stream that curved high in the air, and then disappeared in the seam where the red plastic joined the metal. Over the headset I said, "Hey, Charley ... I think it's found a way."

"Yeah, I see it. Fuck a duck."

Charley was scrambling into the backseat. Already particles were beginning to fill the inside of the car, making a gray fog that rapidly darkened. Charley coughed. I couldn't see what he was doing, he was down below the window. He coughed again.

"Charley?"

He didn't answer. But I heard him swearing.

"Charley, you better get out."

"Fuck these guys."

And then there was an odd sound, which at first I couldn't place. I turned to Mae, who was pressing her headset to her ear. It was a strange, rhythmic rasping. She looked at me questioningly.

"Charley?"

"I'm-spray these little bastards. Let's see how they do when they're wet."

Mae said, "You're spraying the isotope?"

He didn't answer. But a moment later he appeared in the window again, spraying in all directions with the Windex bottle. Liquid streaked across the glass, and dripped down. The interior of the car was growing darker as more and more particles entered. Soon we couldn't see him at all. His hand emerged from the black, pressed against the glass, then disappeared again. He was coughing continuously. A dry cough.

"Charley," I said, "run for it."

"Ah fuck. What's the point?"

Bobby Lembeck said, "Wind's ten knots. Go for it."

Ten knots wasn't enough but it was better than nothing.

"Charley? You hear?"

We heard his voice from the black interior. "Yeah, okay ... I'm looking-can't find-fucking door handle, can't feel ... Where's the goddamn door handle on this-" He broke into a spasm of coughing.

Over the headset, I heard voices inside the lab, all speaking rapidly. Ricky said, "He's in the Toyota. Where's the handle in the Toyota?"

Bobby Lembeck: "I don't know, it's not my car."

"Whose car is it? Vince?"

Vince: "No, no. It's that guy with the bad eyes."

"Who?"

"The engineer. The guy who blinks all the time."

"David Brooks?"

"Yeah. Him."

Ricky said, "Guys? We think it's David's car."

I said, "That's not going to do us any-"

And then I broke off, because Mae was pointing behind her to the backseat of our car. From the seam where the seat cushion met the back, particles were hissing into the car like black smoke.

I looked closer, and saw a blanket on the floor of the backseat. Mae saw it, too, and threw herself bodily into the back, diving between the seats. She kicked me in the head as she went, but she had the blanket and began stuffing it into the crack. My headset came off, and caught on the steering wheel as I tried to climb back to help her. It was cramped in the car. I heard a tinny voice from the earpieces.

"Come on," Mae said. "Come on."

I was bigger than she was; there wasn't room for me back there; my body jackknifed over the driver's seat as I grabbed the blanket and helped her stuff it. I was vaguely aware that the passenger door banged open on the Toyota, and I saw Charley's foot emerge from the black. He was going to try his luck outside. Maybe we should, too, I thought, as I helped her with the blanket. The blanket wouldn't do any good, it was just a delaying tactic. Already I sensed the particles were sifting right through the cloth; the car was continuing to fill. The air was getting darker and darker. I felt the pinpricks all over my skin. "Mae, let's run."

She didn't answer, she just kept pushing the blanket harder into the cracks. Probably she knew we'd never make it if we went outside. The swarms would run us down, get in our path, make us slip and fall. And once we fell, they would suffocate us. Just as they did to the others. The air was thicker. I started to cough. In the semidarkness I kept hearing a tinny voice from the headsets. I couldn't tell where it was coming from. Mae's headset had fallen off, too, and I thought I had seen it on the front seat, but now it was becoming too dark to see. My eyes burned. I coughed continuously. Mae was coughing, too. I didn't know if she was still stuffing the blanket. She was just a shadow in the fog.

I squeezed my eyes against the sharp pain. My throat was tightening, and my cough was dry. I felt dizzy again. I knew we couldn't survive more than a minute or so, perhaps less. I looked back at Mae, but couldn't see her. I heard her coughing. I waved my hand, trying to clear the fog so I could see her. It didn't work. I waved my hand in front of the windshield, and it cleared momentarily.

Despite my fit of coughing, I saw the lab in the distance. The sun was shining. Everything looked normal. It was infuriating that it should appear so normal and peaceful while we coughed ourselves to death. I couldn't see what happened to Charley. He wasn't in front of me anywhere. In fact-I waved my hand again-all I saw was-

Blowing sand.

Jesus, blowing sand.

The wind was back up.

"Mae." I coughed. "Mae. The door."

I don't know if she heard me. She was coughing hard. I reached for the driver's side door, fumbling for the handle. I felt confused and disoriented. I was coughing continuously. I touched hot metal, jerked it down.

The door swung open beside me. Hot desert air rushed in, swirling the fog. The wind had definitely come up. "Mae."

She was racked with coughing. Perhaps she couldn't move. I lunged for the passenger door opposite me. My ribs banged on the gearshift. The fog was thinner now, and I saw the handle, twisted it, and shoved the door open. It banged shut in the wind. I pushed forward, twisted, shoved it open again, holding it open with my hand.

Wind blew through the car.

The black cloud vanished in a few seconds. The backseat was still dark. I crawled forward, out the passenger door, and opened the back door. She reached to me, and I hauled her out. We were both coughing hard. Her legs buckled. I threw her arm over my shoulder and half carried her out into the open desert.

Even now, I don't know how I made it back to the laboratory building. The swarms had vanished; the wind was blowing hard. Mae was a dead weight on my shoulders, her body limp, her feet dragging over the sand. I had no energy. I was racked with spasms of coughing, which often forced me to stop. I couldn't get my breath. I was dizzy, disoriented. The glare of the sun had a greenish tinge and I saw spots before my eyes. Mae was coughing weakly; her breaths shallow. I had the feeling she wouldn't survive. I trudged on, putting one foot ahead of the other. Somehow the door loomed in front of me, and I got it open. I brought Mae into the black outer room. On the other side of the glass airlock, Ricky and Bobby Lembeck were waiting. They were cheering us on, but I couldn't hear them. My headset was back in the car. The airlock doors hissed open, and I got Mae inside. She managed to stand, though she was doubled over coughing. I stepped away. The wind began to blow her clean. I leaned against the wall, out of breath, dizzy.

I thought, Haven't I done this before?

I looked at my watch. It was just three hours since I had narrowly escaped the last attack. I bent over and put my hands on my knees. I stared at the floor and waited for the airlock to become free. I glanced over at Ricky and Bobby. They were yelling, pointing to their ears. I shook my head.

Couldn't they see I didn't have a headset?

I said, "Where's Charley?"

They answered, but I couldn't hear them.

"Did he make it? Where's Charley?"