by Mark Alpert
“Dad, don’t worry. I’ll be all right.” I extend one of my Quarter-bot’s hands and rest it on his shoulder. “It’s a simple operation. There are a million pieces of junk stuck in Brittany’s brain, and I have five million tow trucks to pull them out. That’ll be more than enough.”
Dad shakes his head. “This procedure is not simple. Do you want me to make a list of all the things that could go wrong?”
I give his shoulder a squeeze. The tactile sensors in my steel fingers tell me how much pressure to apply. “I got this, Dad. Really.”
He looks up at my Quarter-bot’s cameras. I’m more than a foot taller, so he has to tilt his head back pretty far. “Just be careful. I love you, Adam.”
This statement seems to give him strength. And it gives me strength too. It reminds me of everything we’ve accomplished together, all the miracles of survival and transformation. Dad can be really annoying sometimes, but we’re a pretty good team.
“I love you too. I’ll be back in a flash.”
Then I let go of his shoulder and start transferring my data to the nanobots.
This transfer is much more complicated than the usual wireless leap from one machine to another. I’m broadcasting my mind to five million antennas, each connected to a tiny capsule of neuromorphic circuits. Each capsule is way too small to hold all my data, so I divide my software into packets and spread them among the swarm of machines. My mind splinters into millions of pieces, fracturing all my emotions and memories. For a thousandth of a second, I’m no longer Adam Armstrong. I’m just a jumble of perceptions without a coordinating identity or consciousness. But then my thoughts come back together through the radio links between the nanobots, which reassemble my software as they exchange billions of wireless signals. My mind is inside the swarm now, occupying and controlling it.
By this point, the nanobots are scattered up and down the whole length of the cephalic vein, from Brittany’s wrist to her shoulder. Each cylindrical machine has a microscopic infrared camera at its front end, and when I turn on the microcameras, I see five million video feeds all at once. It’s really confusing at first, but after a few milliseconds I adjust my circuits so I can make sense of all the information. I compile the millions of viewpoints until they coalesce into a single picture, a panorama of this section of Brittany’s circulatory system.
Although the cephalic vein is less than three millimeters in diameter, from the perspective of my nanobots, it looks wider than the Lincoln Tunnel. And oddly enough, the vein’s inner walls resemble those in a tunnel, because they’re lined with flat, diamond-shaped cells that look like tiles. But instead of being jammed with cars and trucks and buses, this tunnel is filled with the pale liquid called plasma and a vast, fantastic parade of blood cells.
I check my databases again to identify all the things floating alongside my nanobots. The most abundant objects are the red blood cells, small dark disks tumbling in the current, their surfaces coated with hemoglobin and carbon dioxide. Bobbing among them are the white blood cells, the body’s defenders against infection, bulging spheres studded with scary horns and barbs that can tear foreign microorganisms to shreds. And scattered everywhere are cell fragments called platelets, yellowish bits of protein that clump on the vein’s walls, cementing the gaps and fissures.
All in all, it’s the most amazing thing I’ve ever seen. I can’t help but compare Brittany’s anatomy with the circuits of Zia’s Pioneer, the neuromorphic control unit I jumped into just an hour ago. Although Zia’s thoughts were wildly complex, the design of her hardware was easy to understand, so straightforward it was almost boring. But you could never say that about human biology. It’s so much less predictable than electronics. It’s so much more of a mystery.
Because the nanobots are densely concentrated in the vein, I see large numbers of them from each of my microcameras. My swarm is like a fleet of minuscule submarines, all cruising in the same direction. Brittany’s blood rushes and pulses, pushing my nanobots downstream. I’m impressed by how well designed the cylindrical machines are. They’re perfectly shaped for navigating the blood vessels.
In a few seconds, my swarm flows into a larger vein beneath Brittany’s collarbone, and then the blood from her arms merges with the blood descending from her head, and the whole rushing deluge plunges toward her heart. My nanobots funnel into the chambers on her heart’s right side, first the atrium and then the ventricle. As blood pours into the right ventricle, it expands like a balloon, because the pulmonary valve on the other side of the chamber is closed. But then the heart’s muscular walls contract with crushing force and open the valve, pumping blood cells and nanobots toward Brittany’s lungs.
The current slows as my swarm enters the pulmonary capillaries, the vessels in the lungs where gas molecules flow into and out of the blood. The red blood cells turn bright scarlet as they release carbon dioxide and absorb oxygen. Then the bloodstream carries my nanobots back to Brittany’s heart, which contracts once again with booming force and propels my swarm to the aorta, the biggest of all the blood vessels.
Up ahead is a curve in the aorta where smaller arteries branch off to different parts of the body. I send a signal to the navigation systems in my nanobots and steer them toward the carotid arteries that lead to Brittany’s brain. The swarm flows through these blood vessels up her neck and into a narrow passageway on the underside of her skull.
Then the journey becomes more complicated. I need to direct the swarm to all the brain regions that Sigma injured. I steer some of the nanobots to the anterior cerebral artery, some to the orbitofrontal artery, and some to the prefrontal sulcal artery. The MRI map of Brittany’s brain is in my databases, showing dozens of blackened areas in her frontal lobe. To fully restore her consciousness, I have to clear the debris from all the damaged areas.
The current slows again as my swarm flows into the frontal lobe’s cortex, the folded and furrowed layer of brain tissue where most of the higher-level thinking takes place. The arteries snake along the cortical folds, narrowing as they delve deeper into the tissue. The blood vessels branch into slender capillaries, each less than a hundredth of a millimeter wide.
The capillaries here are so cramped that my nanobots have to travel in single file, bumping against the blood cells and platelets. The red blood cells darken as they release their oxygen molecules, which seep through the walls of the blood vessels to feed the brain tissue on the other side. Then the nanobots at the leading edge of my swarm reach one of the damaged regions, a cortical fold where the capillaries are twisted and torn and scarred with clotting platelets. A moment later, I see what caused the damage. Huge metallic structures have breached the walls of the blood vessels and extended into Brittany’s brain tissue.
The structures look like giant black pitchforks. Each is tipped with at least a dozen long spikes that have pierced and mangled the intricate web of brain cells. The spikes have already killed the nearby cells, which have shed their branching tendrils and shriveled into wrinkled husks. Worse, the pressure from the spikes and the layer of dead tissue is killing cells that are farther away. As these brain cells wither and die, they pull their tendrils away from one another, breaking the connections of Brittany’s mind. She’s losing the mental links that define who she is and how she thinks. And when those links rupture, all the characteristics that make her so wonderful—her sense of humor, her physical agility, her repertoire of cheerleading routines and memorized Lady Gaga lyrics—will disappear. She won’t die, but her soul will dissolve.
Seeing the damage makes me desperate. I want to smash the giant pitchforks to bits. I aim my microcameras at one of the structures to get a closer look and see that it’s made of thousands of deactivated nanobots, linked end to end by tiny grappling hooks. The machines were designed to assemble into wires and antennas at Sigma’s command, enabling the AI to take control of a human’s nervous system. But the nanobots in the pitchfork are now broken and rust
ing, so badly damaged that their batteries can’t even hold a charge. And they’re jammed so deep inside the brain tissue that they can’t be dislodged by the body’s normal repair mechanisms.
As my swarm spreads across Brittany’s brain to all the damaged areas, I identify ten thousand structures similar to this one. Then I send a radio message to Dad.
Okay, I’m in the brain and I’ve located the dead nanobots. They’re assembled into large structures that are damaging the brain tissue. I’m going to calculate the most efficient way to dismantle those things.
Do you have enough time? Dad sounds nervous, of course. Won’t the bloodstream push your swarm out of the brain and back to the heart?
The current in the capillaries is weak, and I’ve turned on the propellers in my nanobots. They can stay in position for as long as necessary.
All right, that’s good. But when you disassemble the dead nanobots, make sure you don’t damage the ones in your swarm. If you lose too many of them, you won’t have enough memory capacity for your software.
Now Dad’s being totally ridiculous. My swarm has enough storage capacity to hold the minds of all the Pioneers. What’s more, my software has multiple copies of all my databases, as well as error-correction algorithms that constantly compare the copies and fix the discrepancies. Even if hundreds of thousands of my nanobots are destroyed, I wouldn’t lose a single byte of data. Dad, of all people, should know this, because he invented these circuits and algorithms. All neuromorphic electronics, including the circuits that Sigma used, are based on his designs.
But I’m not going to point out this fact. It’s better to just reassure him.
I’ll be careful. I’ll radio you again when I’m done.
After half a second, I devise a plan for breaking up the pitchfork structures. The nanobots in my swarm have grappling hooks too, and I can use them to pull the dead machines apart. The procedure is pretty complicated, and I have to do the same thing for all of the ten thousand structures stuck in Brittany’s brain. But I have five million nanobots at my command, and that makes the task a lot easier.
I put the plan in motion, and a complex microscopic dance begins. My nanobots surround the giant pitchforks and latch on to their metallic edges. Then the machines turn their propellers in reverse and rip the structures apart, piece by piece. It’s like a colony of ants picking at a dead animal and carrying off the morsels. The nanobots tear off scraps of steel and silicon from the pitchforks and tow the debris to the nearest capillary. Then they release the bits of garbage into Brittany’s bloodstream, which flushes them out of her brain. Her kidneys will filter the junk from her blood, and eventually she’ll pee it all out. Ingenious, right?
The hardest part is coordinating the swarm and making sure the nanobots don’t collide with one another or clog Brittany’s blood vessels. But my software is good at solving this kind of problem, and within a minute the disassembly process is moving along briskly. The nanobots whittle down the black pitchforks and haul away the debris. They shuttle back and forth between the brain tissue and the capillaries, steady and tireless. After only fifteen minutes, most of the metallic structures are gone. The nanobots also cart away the dead brain cells, relieving the pressure on the neighboring cells that are injured but still alive. The surviving nerves stretch toward each other, rebuilding their connections.
Very soon, only the largest pitchfork is left, a monstrous structure with dozens of spikes piercing Brittany’s prefrontal cortex. I consolidate my swarm, steering all the nanobots to the remaining structure. Five million machines converge on the hunk of black steel and swiftly rip it apart. They break off the spikes, one by one. Then the swarm attacks the pitchfork’s shaft, ripping metallic sheets off the thick column. After five more minutes, I’ve reduced the structure to a stump, less than a millimeter long, embedded in a layer of dead brain cells. Hundreds of nanobots latch on to the stump’s jagged ends and pull in opposite directions. The structure disintegrates into a thousand pieces.
My nanobots collect the last bits of debris and tow them toward the closest capillary. But as I train my microcameras on the area to give it a final inspection, I notice something strange. There’s a gap in the dead brain tissue where the giant pitchfork formerly stood, and floating within the gap is a tiny black sphere, only a thousandth of a millimeter wide.
At first I assume it’s just an oddly shaped piece of debris. But then the sphere expands. In less than a microsecond, it doubles in size.
This is definitely alarming. Is it a booby trap? Maybe an explosive device that Sigma hid inside one of its machines? If so, I have to be very careful. I certainly don’t want to set off an explosion in the middle of Brittany’s brain.
I steer fifty nanobots toward the gap in the brain tissue, moving them slowly and cautiously. Keeping their distance from the black sphere, the nanobots aim their sensors at the foreign object. At the same time, I tell myself to stay calm, stay logical. Everything will be all right as long as I respond logically. First, I have to find out what that sphere is made of. And then, if it’s really an explosive device, I’ll figure out a way to defuse it. No problem. I can do this.
But I don’t get any readings from my sensors. Electromagnetic waves don’t reflect off the sphere, and sound waves don’t bounce off it either. The sphere isn’t made out of steel or silicon. It’s not even solid. It’s more like a hole, absorbing anything that comes near it. The waves that touch its surface simply vanish.
Then the sphere expands again, ballooning to ten times its original size. It sucks in the dead brain cells on either side of it, consuming them instantly. I try to pull back my nanobots, turning their propellers in reverse, but a moment later the sphere expands once more. It engulfs a whole layer of dead cells and all fifty of the nanobots surrounding it.
Now I start to panic. This doesn’t make sense. The sphere is violating the laws of physics. I search all my databases, frantically seeking an explanation, but I can’t find anything like this. The only phenomenon that comes close is from astronomy, the concept of the black hole, an infinitely dense object that’s created when a dying star collapses. But a black hole pulls matter toward it because of its intense gravity, and there’s no gravitational force coming from the mysterious black sphere. It’s simply a bubble of nothingness, expanding and devouring everything around it.
My circuits shiver. I hear a voice deep inside my electronics, a faint echo in my memory files: I call it the Silence.
A bolt of terror runs through my swarm, arcing wirelessly to all my nanobots. The sensation is violently and painfully familiar. It’s like the terror that hit me yesterday when I waved good-bye to Amber’s Jet-bot in the desert. Except this time the pain and panic don’t subside. Instead, the roiling emotions grow stronger as they whirl across my swarm’s radio links.
I realize with horror that a surge is building inside me. This is the worst possible moment for it. If I release the surge now, the energy will scorch Brittany’s brain tissue. It’ll incinerate her mind.
I need to stop the surge. I need to hold back my fear. So I try to restrain my emotions, to calm myself. But as I struggle to do this, the black sphere balloons again, tripling in size. The nothingness consumes more than a hundred of Brittany’s brain cells and a long stretch of a nearby capillary. It also devours another thousand of my nanobots, including one that transmits a radio signal just as the sphere swallows it.
This signal ricochets across the rest of my swarm. It leaps from one antenna to another, reaching millions of nanobots in less than a hundredth of a second. It spreads to nearly all my machines before I notice that the radio transmission contains a hidden piece of malware, a block of software code designed to infect my nanobots. It’s like a computer virus, but more destructive than anything I’ve ever seen. It doesn’t just erase the data in my machines. It erases their hardware too. It dissolves their logic gates and transistors and microprocessors. A black sphere gro
ws within each of my nanobots and starts to melt its wires. The nothingness is devouring me from the inside.
I hear the faint voice again, ruthless and all-knowing: Those are the Sentinels. They guard the Silence.
The terror rises in my circuits, choking my thoughts. I have to escape! I have to abandon the swarm and transfer back to my Quarter-bot! But the malware has already corrupted my communications systems, making it impossible to connect to my Quarter-bot’s radio. The black spheres are ravaging the transmitters in my nanobots, and I can barely maintain the data links between them. I don’t even have enough power to transmit an SOS to Dad. I can receive the emergency messages he’s sending me, but I can’t respond.
Adam! Your radio just went down! What’s wrong? Can you hear me?
There’s only one option left. I withdraw all my software from the infected nanobots and retreat to the small part of the swarm that the malware hasn’t reached yet. Only 16,349 nanobots are uninfected, but together they have enough circuitry to hold my data. In a millionth of a second I devise a network firewall that stops the malware from infiltrating my remaining machines. Then I transmit a simple order to those nanobots: RUN!
Spinning their propellers at full speed, my machines rush out of the brain tissue and back to the capillaries. They charge through the narrow blood vessels, shoving the cells and platelets aside, and stream into the sagittal vein that curves over Brittany’s frontal lobe. My diminished swarm follows this vessel to the back of her head, then cascades down her neck through the jugular vein. But as my nanobots hurtle toward Brittany’s heart, I turn their microcameras backward and see what I was afraid I’d see. The machines I abandoned—the millions of infected nanobots—are pursuing my swarm. They’re just a few centimeters behind.