The next five minutes were tense. The swarm retraced its path, going back to the rabbit. It swirled around the rabbit for a while, moving in slow semicircles back and forth. Then once again it retraced the route back to the power station door. It stayed at the door for a while, then returned to the rabbit.
The swarm repeated this sequence three times. Meanwhile, the other swarms had continued their zigzagging around the building, and were now out of sight. The solitary swarm returned to the door, then headed back to the rabbit again.
“It’s stuck in a loop,” Charley said. “It just does the same thing over and over again.”
“Lucky for us,” I said. I was waiting to see if the swarm would modify its behavior. So far it hadn’t. And if it had very little memory, then it might be like an Alzheimer’s patient, unable to remember it had done all this before.
Now it was going around the rabbit, moving in semicircles.
“Definitely stuck in a loop,” Charley said.
I waited.
I hadn’t been able to review all the changes they’d made to PREDPREY, because the central module was missing. But the original program had a randomizing element built into it, to handle situations exactly like this. Whenever PREDPREY failed to attain its goal, and there were no specific environmental inputs to provoke new action, then its behavior was randomly modified. This was a well-known solution. For example, psychologists now believed a certain amount of random behavior was necessary for innovation. You couldn’t be creative without striking out in new directions, and those directions were likely to be random-
“Uh-oh,” Mae said.
The behavior had changed.
The swarm moved in larger circles, going around and around the rabbit. And almost immediately, it came across another path. It paused a moment, and then suddenly rose up, and began to move directly toward us. It was following exactly the same path we had taken, walking to the shed.
“Shit,” Charley said. “I think we’re fucked.”
Mae and Charley rushed across the room to look out the window. David and Rosie stood and peered out the window above the sink. And I started to shout: “No, no! Get away from the windows!”
“What?”
“It’s visual, remember? Get away from the windows!”
There was no good place to hide in the storage room, not really. Rosie and David crawled under the sink. Charley pushed in beside them, ignoring their protests. Mae slipped into the shadows of one corner of the room, easing herself into the space where two shelves didn’t quite meet. She could only be seen from the west window, and then not easily. The radio crackled. “Hey guys?” It was Ricky. “One’s heading for you. And uh… No… two others are joining it.”
“Ricky,” I said. “Go off air.”
“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.”