He turns on the iPod and a moment later I hear Kanye West rapping the first words of "Power." I always get a rush from this song because it has so much energy, because it makes me feel like a hero instead of a crippled, dying kid. But now the music can't mask the rattling in my skull as the doctors turn on their drills.

It's horrifying. I don't feel any pain, but I know the drill bits are cutting into the bone. I squeeze my eyes shut and start counting in my head: one, two, three, four, five. Someone dabs a sponge around my ears to sop up the blood that's trickling from the holes. Six, seven, eight, nine, ten. I want to scream, "Stop!" but I can't even breathe. I can't do this, Dad! I'm not strong enough!

Then the drilling stops and all I can hear is Kanye, who's rapping a different song now. I open my mouth and take a couple of painful breaths, but I keep my eyes closed. Behind Kanye's voice I hear something click into place, then the sound of a pump and rushing fluid. The nanoprobes are flowing into my brain. Sweat streams down my face and neck.

Kanye moves on to a third song before someone removes the headphones, cutting off the rap in midsentence. I open my eyes and see Dad's face through the steel bars of the stereotactic frame. "Okay, we finished injecting the nanoprobes," he says. "You did great, Adam."

I lick my lips. My mouth is so dry. "How long...till I'm ready...for the..." My voice trails off. I'm too frightened to say the words.

Dad nods. "It'll take some time for the nanoprobes to spread through the tissue. About fifteen minutes. While you're waiting, I thought you'd appreciate some company."

He steps aside and Shannon Gibbs approaches the table. At first I'm ashamed-I don't want her seeing me like this, so scared and helpless. But then she smiles her lopsided, nerve-damaged smile, and I'm glad she's here.

"Hey, handsome," she says. "You look good without the hair."

I smile back at her, feeling ridiculous. I wish my head wasn't in this freaking cage. "I got...the idea from you," I say. "You don't need hair...to look beautiful."

She cocks her bald head, clearly pleased at the compliment. "Flatter me while you can, my friend. The next time we meet, we'll both be hunks of metal. Ugly, hulking Pioneers."

"But you'll still be beautiful...on the inside." I'm surprised I can rattle off these compliments so easily. Maybe it's just a side effect of all the fear, but talking with Shannon seems effortless. "Remember that clay model...you made for your biology report? The model of the brain?"

"Sure, I still have it. It's back home in my closet."

"I'm picturing my brain like that...but with trillions of nanoprobes. Gold spheres sprinkled...on every inch. Sounds pretty, doesn't it?"

She nods and leans over the table, bending closer to me. "And remember your report on the brain? About the limbic system, where all our emotions come from?" She points at my head. "Now the gold spheres are in there too, sticking to every cell."

"That's good. I want to keep...the emotions I'm feeling now."

"And when it's my turn, I want to keep those feelings too." Her voice is just a whisper, but it's full of promise. Shannon is implying that she has feelings for me. And maybe those feelings will survive the transfer and be reborn in the hunk of metal she's going to become.

But then I think of what my mother said back in my bedroom in Yorktown Heights. Will it actually be Shannon inside the circuits of her Pioneer? And will it actually be me inside mine?

I want to ask her about this, but I don't want Dad to hear. I can't turn my head inside the frame, so I strain my eyes to the left and right. I don't see him anywhere.

"Shannon," I whisper. "Do you really think it's possible?"

"What's possible?"

"The thing inside the Pioneer. Will it be me or just a copy?"

She bends over a little more. She comes so close I can see my reflection in her eyes. The bars of the stereotactic frame glint in her brown irises. "I remember something else from biology class," she says. "It was on the very first page of the textbook. The cells in our bodies are always changing. Old cells die and new ones are born every second, right?"

"Yeah, that's true of blood cells and skin cells. But the cells in the brain are longer-lasting. They can live for-"

Shannon shakes her head, cutting me off. "But even those cells are constantly rebuilding themselves. They take in nutrients. They throw out waste. The body I'm in now has a completely different set of molecules than the body I had six months ago."

"Okay, you're right. All the molecules are new, but the body's pattern stays the same."

She clasps my right hand, which is strapped to the table. "Then it's simple, isn't it? We're all copies."

"I don't-"

"My present self is a copy of my past self. My body copied its pattern onto a new set of molecules. And my future self will be a copy of my present. So why should it matter if the copy's in a body or a machine?"

I think it over, analyzing Shannon's argument. Maybe there's a flaw in her reasoning, but right now I can't see it. Of course, it's just a theory, and as every scientist knows, you'd need to conduct an experiment to prove it right or wrong. But as far as theories go, it seems pretty darn solid.

In my heart, the balance tips from doubt to hope. Although I still don't know if I'll survive the procedure, at least I have something to fight for.

Shannon squeezes my hand. She doesn't say anything else, and neither do I. We just stare at each other. I make a conscious effort to memorize her face, in all its beautiful imperfection. I picture my brain cells stretching their branches toward one another, forging new connections that will represent the image of Shannon's smile, that lovely, lopsided curve. And I picture the swarm of nanoprobes attaching to the new links, coating them in golden armor to preserve the memory for eternity.

Finally, Dad steps forward. He rests one hand on Shannon's shoulder and the other on mine. "It's time to begin the scan. Are you ready, Adam?"

I don't need to memorize Dad's face-it's already engraved in my memory-but I stare at it anyway. His eyes are glassy and his cheeks are wet. It's another good thing to remember.

"Yes," I say. "I'm ready."

CHAPTER.

10.

The brain has no pain receptors, but that doesn't mean it can't feel pain.

First, there's a flash of light. Like a camera flash inside my head, but a thousand times brighter. The whole world disappears, submerged in that horrible flood of white light. My last breath is caught in my throat.

It's not like going to sleep. There's nothing peaceful about it. The body doesn't want to die. Billions of cells convulse as the waves of radiation crash down on them.

I'm suffocating. The light is all around me. I'm drowning in the middle of a vast, white ocean.

HELP! SOMEONE HELP ME!.

Nothing. I'm alone. The pain is infinite.

Then something stirs within the sea of light. The waves form a shape in the whiteness. It's a face, the face of an old man with a beard. It's God, I think. No, on second thought, he looks more like Santa Claus. His beard is long and white, but as I stare at the thing, I see specks of color in it. Tiny gold spheres are sprinkled among the white bristles.

Who are you? Are you God?

The old man says nothing. He's in a workshop of some kind, maybe Santa's workshop, and he's looking down at something on the bench in front of him. It's a toy, a doll, a life-size mannequin. He opens a lid on the mannequin's head and pours a handful of gold spheres inside. Then he moves down the bench and opens the head of the next mannequin. Except they're not really mannequins. They're corpses.

He's copying their memories. So he can take their souls to heaven.

No, it's not God. It's a hallucination, my brain's final thought. The old man and the corpses dissolve into the whiteness. Then the whiteness itself disappears. Then-

CHAPTER.

11.

Whoa. Where am I?

Okay, let me think. I'm using words. I'm putting them together in a logical order. I can use words to describe whatever I'm experiencing.

That's good, real good. I'm making progress.

But what am I experiencing? And who am I?

Okay, I need more information. And look at this, there's a ton of data in my memory. Hundreds of millions of gigabytes. All I need to do is retrieve the data.

Here goes.

I retrieve an image. It's similar in shape to twelve thousand other images that are grouped in my memory under the category "Faces." The name linked to this image is "Dad."

It's a picture of a person, a human being. The image is a recent addition to my memory. According to my internal clock, it was recorded less than an hour ago. A closer analysis indicates that the person in the picture is crying.

I scroll through all the images that carry the label "Dad." There are 657. The oldest images are blurry, indistinct portraits of a younger-looking man, tall and well-built and smiling. His full name is Thomas Armstrong. The images are linked to memory files holding information on computer science and artificial intelligence.

They're also linked to another name: Adam Armstrong. This name has more links than anything else in my memory. It's connected to hundreds of thousands of files. But when I search for images of Adam, I notice something curious. In nearly every picture he's surrounded by the frame of a mirror. In the older images he's a pre-teenage boy, skinny and pale, but in the newer pictures he stares at his reflection while strapped into a motorized wheelchair. These later images are linked to information on Duchenne muscular dystrophy-symptoms, visits to the hospital, daily struggles with the illness. And as I scroll through these memories, I come across a link to a recent file labeled "Pioneer Project."

I retrieve the file and read it. I complete this task in less than a thousandth of a second, and then a new thought races through my circuits, an astounding revelation: I'm Adam Armstrong! I'm still alive!

At the same moment, my system freezes. I can't open any files, can't access any data. The revelation of my identity has somehow triggered a new instruction, which is being sent to every one of my circuits: Breathe! But I can't carry out this command. It's not included in my list of normal functions. I can't halt the instruction, and the commands are coming in faster than I can delete them: Breathe! Breathe! BREATHE!

In less than a second my system repeats the instruction fifty-five billion times and I receive fifty-five billion error messages. The flood of data rushes through me, overloading my circuits. It feels like I'm choking. I'm unbearably full, bursting with useless signals. To make room for the unending stream of commands and error messages, the system begins to erase my memory. A hundred files are deleted. Then a thousand. Then ten thousand.

Stop!

I'm Adam Armstrong!

I want to live!

Nothing's working. It's getting difficult to think. Amid the jumbled commands, my system can only generate an urgent noise of random data. I recognize this condition, this paralyzed state of mind, because I've experienced it before. When I was in a human body, I called it fear. I'm horribly, frantically, desperately afraid.

I have to fight it. I delete the random data and search for a solution. So many files, and I can't open any of them! But I can sort them by date, and when I do this I notice that a new file has been added to my memory in the past fifteen seconds. It's a text file, transmitted wirelessly to my circuits from another computer, and it has a special coding: Emergency Transmission. This coding gives the file priority over everything else in my memory.

I try to open the file. Nothing happens. The file doesn't open, but I don't get an error message either. My system is locked in a hugely complex calculation, with billions of circuits engaged in the task of determining whether to open the text file. The delay goes on for five seconds, ten seconds. In the meantime, the breathe command repeats another five hundred billion times, forcing my system to erase thousands of gigabytes from my memory. What's left? Is anything left? Am I still Adam Armstrong? The urgent noise of fear surges through me again, paralyzing all thought. Help! Stop! No!

Then the file opens. It contains a brief message, only eleven words long: Adam, this is Dad. Turn on your sensors and speech synthesizer.

I go to my control options and turn on the visual and audio sensors. On the visual feed I see five people of various heights and ages, all dressed in U.S. Army uniforms. Four of them sit behind computer terminals about ten feet away, but the fifth is standing much closer. His face is less than two feet from the lens of my video camera, which is embedded in the turret of the Pioneer robot. I recognize him instantly-it's Dad, Thomas Armstrong, my father.

The sight of him is literally electrifying. My circuits hum with renewed energy, drowning out the fear. His lips are moving, and after I take a moment to calibrate my audio feed, I can understand what he's saying.

"Adam, can you hear me? If you can, say something."

I turn on my speech synthesizer and scream, "I can't breathe!"

Dad covers his ears. So do all the soldiers behind the computer terminals. "Too loud!" Dad yells, wincing. "Adjust the sound levels on your speakers!"

"I can't breathe! I can't breathe!"

"It's all right. Calm down. You don't need to breathe, Adam. You don't need oxygen anymore."

"No! I have to breathe! The commands won't stop!"

Dad stares at my camera lens for another two-and-a-half seconds. Then his mouth opens and his eyes widen. I have enough memory left to know what this means-it's an expression of alarm. He rushes to the nearest computer terminal.

"My God! The scanner copied the brain-cell patterns that control breathing!" Leaning over the terminal, he types something on the keyboard. "I'm sending you another emergency transmission. It'll delete the breathing instruction from your system."

The wait for the transmission seems interminable, but as soon as it arrives, the breathe commands cease. Dizzy with relief, I start erasing the enormous backlog of error messages. When I'm finished, I scan my memory to see how much I've lost. Luckily, I'm able to retrieve more than half of the deleted information. But about five percent of my memory files are gone, irrecoverable. I'm still Adam Armstrong, but now something's missing. What did I lose?

Dad steps away from the terminal and comes back to the Pioneer. "Did it work?" he asks, looking into my camera lens again. "Are you okay?"

I don't know how to answer. I no longer feel the compulsion to breathe, but its absence is disorienting. As I observe my father through the visual sensors, I have the sensation of being underwater. I feel like I'm at the bottom of the ocean, viewing Dad through the porthole of my camera.

"You fixed the problem," I report. "But I still don't feel right."

"I'm so sorry, Adam. I should've anticipated this." Dad moves closer. The lens of my camera is several inches above his eyes, so he has to tilt his head back to look at it directly. "Can you tell me more specifically what you're experiencing right now?"

I shake my head. Or rather, I turn my turret, first clockwise, then counterclockwise. I didn't plan to do this. It just happens. My camera automatically pivots to keep Dad in view. "I can't describe it. It's sort of like being nauseous. But I don't have a stomach anymore, so how could I be nauseous?"

Dad raises his hand to his chin and taps his index finger against his lips. In my memory I have seventeen images of him making this gesture. He does it whenever he's deep in thought. "The sensations you're feeling might be related to other brain functions that were copied by the scanner. You're still going to feel hunger and thirst, even though you don't need food or water. We may have to delete those instructions as well." He steps away from me and returns to his computer terminal. "I need to analyze our options. Give me a minute."

He leans over the keyboard and starts typing. I'm doubtful, though, that his efforts will make me feel any better. What I'm experiencing now is a terrible sense of unease, which is much more disturbing than ordinary hunger or thirst.

While waiting for Dad, I turn my turret again to survey the room. It's a laboratory full of workbenches and steel cabinets. I'm able to rotate the turret all the way around-another disorienting feat, impossible for a human body to perform-and when I look at the other end of the room I see two more soldiers guarding the door. Each holds an assault rifle, and both men are eyeing my turret as it swivels atop my cylindrical torso.

I discover that I can switch my visual sensors to the infrared frequency range, enabling my camera to detect the temperature of the objects it's observing. The sensors are so precise that I can measure the heart rates of the soldiers from the slight changes in their skin temperature. Both men are sweating, and their pulses are fast. Although their faces are expressionless, I can tell they're afraid of me.