We had lost the trail.
Exhaustion hit me suddenly, and hard. I had been running on adrenaline all day and now that I was finally defeated a deep weariness came over my body. My eyes drooped. I felt as if I could go to sleep standing on the bike.
Behind me, Mae sat up and said, “Don’t worry, okay?”
“What do you mean?” I said wearily. “My plan has totally failed, Mae.”
“Maybe not yet,” she said.
Bobby pulled up close to us. “You guys look behind you?” he said.
“Why?”
“Look back,” he said. “Look how far we’ve come.”
I turned and looked over my shoulder. To the south, I saw the bright lights of the fabrication building, surprisingly close. We couldn’t be more than a mile or two away. We must have traveled in a big semicircle, eventually turning back toward our starting point. “That’s weird.”
Mae had got off the bike, and stepped in front of the headlamp. She was looking at the LCD readout on the counter. She said, “Hmmm.”
Bobby said hopefully, “So, what do you say, Mae? Time to go back?”
“No,” Mae said. “It’s not time to go back. Take a look at this.” Bobby leaned over, and we both looked at the LCD readout. It showed a graph of radiation intensity, stepping progressively downward, and finally dropping quickly. Bobby frowned. “And this is?”
“Time course of tonight’s readings,” she said. “The machine’s showing us that ever since we started, the intensity of the radiation has declined arithmetically-it’s a straight-line decrease, a staircase, see there? And it’s stayed arithmetic until the last minute or so, when the decrease suddenly became exponential. It just fell to zero.”
“So?” Bobby looked puzzled. “That means what? I don’t get it.”
“I do.” She turned to me, climbed back on the bike. “I think I know what happened. Go forward-slowly.”
I let out the clutch, and rumbled forward. My bouncing headlight showed a slight rise in the desert, scrubby cactus ahead…
“No. Slower, Jack.”
I slowed. Now we were practically going at a walk. I yawned. There was no point in questioning her; she was intense, focused. I was just tired and defeated. We continued up the desert rise until it flattened, and then the bike began to tilt downward-
“Stop.”
I stopped.
Directly ahead, the desert floor abruptly ended. I saw blackness beyond.
“Is that a cliff?”
“No. Just a high ridge.”
I edged the bike forward. The land definitely fell away. Soon we were at the edge and I could get my bearings. We were at the crest of a ridge fifteen feet high, which formed one side of a very wide streambed. Directly beneath me I saw smooth river rocks, with occasional boulders and clumps of scraggly brush that stretched about fifty yards away, to the far side of the riverbed. Beyond the distant bank, the desert was flat again. “I understand now,” I said. “The swarm jumped.”
“Yes,” she said, “it became airborne. And we lost the trail.”
“But then it must have landed somewhere down there,” Bobby said, pointing to the streambed.
“Maybe,” I said. “And maybe not.”
I was thinking it would take us many minutes to find a safe route down. Then we would spend a long time searching among the bushes and rocks of the streambed, before picking up the trail again. It might take hours. We might not find it at all. From our position up here on top of the ridge, we saw the daunting expanse of desert stretching out before us. I said, “The swarm could have touched down in the streambed. Or it could have come down just beyond the bed. Or it could have gone quarter mile beyond.” Mae was not discouraged. “Bobby, you stay here,” she said. “You’ll mark the position where it jumped. Jack and I will find a path down, go out into that plain, and run in a straight line east-west until we pick up the trail again. Sooner or later, we’ll find it.”
“Okay,” Bobby said. “Got you.”
“Okay,” I said. We might as well do it. We had nothing to lose. But I had very little confidence we would succeed.
Bobby leaned forward over his ATV. “What’s that?”
“What?”
“An animal. I saw glowing eyes.”
“Where?”
“In that brush over there.” He pointed to the center of the streambed. I frowned. We both had our headlights trained down the ridge. We were lighting a fairly large arc of desert. I didn’t see any animals.
“There!” Mae said.
“I don’t see anything.”
She pointed. “It just went behind that juniper bush. See the bush that looks like a pyramid? That has the dead branches on one side?”
“I see it,” I said. “But…” I didn’t see an animal.
“It’s moving left to right. Wait a minute and it’ll come out again.” We waited, and then I saw a pair of bright green, glowing spots. Close to the ground, moving right. I saw a flash of pale white. And almost immediately I knew that something was wrong. So did Bobby. He twisted his handlebars, moving his headlamp to point directly to the spot. He reached for binoculars.
“That’s not an animal…” he said.
Moving among the low bushes, we saw more white-flesh white. But we saw only glimpses. And then I saw a flat white surface that I realized with a shock was a human hand, dragging along the ground. A hand with outstretched fingers.
“Jesus,” Bobby said, staring through the binoculars.
“What? What is it?”
“It’s a body being dragged,” he said. And then, in a funny voice, he said, “It’s Rosie.”
DAY 6
10:58 P.M.
Gunning the bike, I took off with Mae, running along the edge of the ridge until it sloped down toward the streambed floor. Bobby stayed where he was, watching Rosie’s body. In a few minutes I had crossed the streambed to the other bank, and was moving back toward his light on the hill.
Mae said, “Let’s slow down, Jack.”
So I slowed down, leaning forward over my handlebars, trying to see the ground far ahead. Suddenly the radiation counter began to chatter again.
“Good sign,” I said.
We moved ahead. Now we were directly across from Bobby on the ridge above. His headlamp cast a faint light on the ground all around us, sort of like moonlight. I waved for him to come down. He turned his vehicle and headed west. Without his light, the ground was suddenly darker, more mysterious.
And then we saw Rosie Castro.
Rosie lay on her back, her head tilted so she appeared to be looking backward, directly at me, her eyes wide, her arm outstretched toward me, her pale hand open. There was an expression of pleading-or terror-on her face. Rigor mortis had set in, and her body jerked stiffly as it moved over low shrubs and desert cactus.
She was being dragged away-but no animal was dragging her.
“I think you should turn your light off,” Mae said.
“But I don’t see what’s doing it… there’s like a shadow underneath her…”
“That’s not a shadow,” Mae said. “It’s them.”
“They’re dragging her?”
She nodded. “Turn your light off.”
I flicked off the headlamp. We stood in darkness. I said, “I thought swarms couldn’t maintain power more than three hours.”
“That’s what Ricky said.”
“He’s lying again?”
“Or they’ve overcome that limitation in the wild.”
The implications were unsettling. If the swarms could now sustain power through the night, then they might be active when we reached their hiding place. I was counting on finding them collapsed, the particles spread on the ground. I intended to kill them in their sleep, so to speak. Now it seemed they weren’t sleeping.
We stood there in the cool dark air, thinking things over. Finally Mae said, “Aren’t these swarms modeled on insect behavior?”
“Not really,” I said. “The programming model was predator-prey. But because the swarm is a population of interacting particles, to some degree it will behave like any population of interacting particles, such as insects. Why?”
“Insects can execute plans that take longer than the lifespan of a single generation. They can build nests that require many generations. Isn’t that true?”
“I think so…”
“So maybe one swarm carried the body for a while, and then another took over. Maybe there have been three or four swarms so far. That way none of them has to go three hours at night.” I didn’t like the implications of that idea any better. “That would mean the swarms are working together,” I said. “It would mean they’re coordinated.”
“They clearly are, by now.”
“Except that’s not possible,” I said to her. “Because they don’t have the signaling capability.”
“It wasn’t possible a few generations ago,” Mae said. “Now it is. Remember the V formation that came toward you? They were coordinated.”
That was true. I just hadn’t realized it at the time. Standing there in the desert night, I wondered what else I hadn’t realized. I squinted into the darkness, trying to see ahead. “Where are they taking her?” I said.
Mae unzipped my backpack, and pulled out a set of night goggles. “Try these.” I was about to help her get hers, but she’d deftly taken her pack off, opened it, and pulled out her own goggles. Her movements were quick, sure.
I slipped on the headset, adjusted the strap, and flipped the lenses down over my eyes. These were the new Gen 4 goggles that showed images in muted color. Almost immediately, I saw Rosie in the desert. Her body was disappearing behind the scrub as she moved farther and farther away.
“Okay, so where are they taking her?” I said again. Even as I spoke, I raised the goggles higher, and at once I saw where they were taking her.
From a distance it looked like a natural formation-a mound of dark earth about fifteen feet wide and six feet high. Erosion had carved deep, vertical clefts so that the mound looked a little like a huge gear turned on edge. It would be easy to overlook this formation as natural. But it wasn’t natural. And erosion hadn’t produced its sculpted look. On the contrary, I was seeing an artificial construction, similar to the nests made by African termites and other social insects.
Wearing the second pair of goggles, Mae looked for a while in silence, then said, “Are you going to tell me that is the product of self-organized behavior? That the behavior to make it just emerged all by itself?”
“Actually, yes,” I said. “That’s exactly what happened.”
“Hard to believe.”
“I know.”
Mae was a good biologist, but she was a primate biologist. She was accustomed to studying small populations of highly intelligent animals that had dominance hierarchies and group leaders. She understood complex behavior to be the result of complex intelligence. And she had trouble grasping the sheer power of self-organized behavior within a very large population of dumb animals.
In any case, this was a deep human prejudice. Human beings expected to find a central command in any organization. States had governments. Corporations had CEOs. Schools had principals. Armies had generals. Human beings tended to believe that without central command, chaos would overwhelm the organization and nothing significant could be accomplished. From this standpoint, it was difficult to believe that extremely stupid creatures with brains smaller than pinheads were capable of construction projects more complicated than any human project. But in fact, they were.
African termites were a classic example. These insects made earthen castlelike mounds a hundred feet in diameter and thrusting spires twenty feet into the air. To appreciate their accomplishment, you had to imagine that if termites were the size of people, these mounds would be skyscrapers one mile high and five miles in diameter. And like a skyscraper, the termite mound had an intricate internal architecture to provide fresh air, remove excess CO2 and heat, and so on. Inside the structure were gardens to grow food, residences for royalty, and living space for as many as two million termites. No two mounds were exactly the same; each was individually constructed to suit the requirements and advantages of a particular site. All this was accomplished with no architect, no foreman, no central authority. Nor was a blueprint for construction encoded in the termite genes. Instead these huge creations were the result of relatively simple rules that the individual termites followed in relation to one another. (Rules like, “If you smell that another termite has been here, put a dirt pellet on this spot.”) Yet the outcome was arguably more complex than any human creation. Now we were seeing a new construction made by a new creature, and it was again difficult to conceive how it might have been made. How could a swarm make a mound, anyway? But I was beginning to realize that out here in the desert, asking how something happened was a fool’s errand. The swarms were changing fast, almost minute to minute. The natural human impulse to figure it out was a waste of time. By the time you figured it out, things would have changed.
Bobby rumbled up in his ATV, and cut his light. We all stood there under the stars. Bobby said, “What do we do now?”
“Follow Rosie,” I said.