I scan the instructions. They make clear, in a playful, user-friendly way, that genes may lay the table for the brain, but they don’t cook the meal. Brains are about experience, too. And even at the genetic level, the interactions are so subtle and so intertwined that you can never be sure what you’re getting. The brain is a tangle of wires, billions and billions of wires, with some areas relatively sparse and other areas so densely packed that the connections seem to fuse, creating something greater than the mere connection of wires.

I scratch my wrist, where a scrap of surgical tape has been left behind. It itches. My whole body’s on edge, the way I feel when I haven’t been able to run for a few days.

Come to think of it, maybe that’s the problem.

No, I tell myself, that’s not the problem. The problem is that one way or another, you’re going to have to confront your mother and tell her you know the truth.

Don’t think about it. Not yet.

I could give Adam a genius-level IQ. I could drag certain icons together and come up with a massively complex brain. One that’s capable of absorbing incredible detail and synthesizing vast quantities of data.

On the other hand, I might also create a person so smart he can’t relate to anyone but people like himself. I could reduce his potential pool of friends, peers, lovers, to one ten-thousandth of one percent of the human race.

I could make it impossible for him to be happy.

Maybe I should make him average. He would have a wide choice of friends and possible lovers. But he’d have to work harder at school. Things might not come quite as easily to him.

He might be happier. But merely making him average wouldn’t ensure that.

I could tilt him toward the arts. I could prepare him for a life of science. I could code him to be a humanitarian.

I could make him fearful and cautious. He would probably live longer. But he might not find what he was looking for and needed.

I could make him reckless and bold. He might die younger. He might be a criminal. He might be a great creative mind.

This is not the simple, fun art work of making a face and a body. I’m not religious, but I’m starting to have some sympathy for God. Give man a brain smart enough to name the animals, one generally useful and productive, and you have to see the whole forbidden apple thing coming down the pike.

This isn’t as easy as it looks.

I think about brains I’ve known. Aislin. What the hell is going on in her brain? She’s not as book-smart as I am, and maybe that gets her into trouble. But at the same time, if you added up all the sheer pleasure and fun we’ve each had? Aislin’s pile would look like a skyscraper next to my three-story townhouse.

And what about my mother? She’s brilliant. Ambitious. Amoral.

You’re a mod. You’re genetically modified.

I can still hear the way Solo said it: a mod. As if that’s a regular word, an entry in Webster’s.

He sounded like a doctor when he told me. A doctor telling his patient she has an incurable illness.

Which is funny, when you think about it, because what I have amounts to a superpower. I can heal with a speed and completeness that’s unbelievable. I could be a comic book hero.

And yet I never noticed.

How smart can I be if I never even noticed?

“He’s … beautiful.”

I turn to see Aislin, pointing to Adam. She’s a disaster. Bruises all over one half of her face. The bandages covering the sutures are stained with seeping blood, now dried to a rust color.

She is not a mod.

“How are you feeling?” I ask. I don’t get up and hug her, although I think maybe I should. I don’t.

She doesn’t answer. Her mouth is hanging open. “Marry me, Adam. I don’t care if you’re missing some parts. I love you.”

“Yeah, his face turned out pretty well,” I say flatly. “So again: How are you?”

Aislin tries to focus. “I’m way hungover. Plus I guess someone must have dropped a safe on me.” She smiles, wincing, and I see a jagged, broken tooth.

When I was seven I broke a tooth after missing a landing on the balance beam. It grew back. How did I not notice how strange that was?

I am silent. Aislin’s lower lip trembles. She is about to cry.

I stand, push back my chair. And I hug her.

Why don’t I want to? Why do I feel as if my skin has been sandpapered and now everything is just too much?

“I have to help Maddox,” she says into my neck.

I push her, hold her out at arm’s length. “Maddox is a drug dealer. A stupid one, no less. He’s a drug dealer who ripped off other drug dealers. And he got you hurt.”

She steps back away from me. “What am I supposed to do? Just let them kill him?”

“How about calling the cops?”

She sighs. “He’ll go to prison.”

“Probably.”

I tap my foot, a parody of my mother. “Aislin. Seriously. What other option do you have?”

Aislin drops into my chair. Near her part, her hair is matted with blood. “I don’t know. I don’t know anything anymore.”

“How much does he owe?” I ask.

“I’m not asking you for money, E.V.”

“How much?” There’s a hard, cynical sound in my voice. I hate myself for using it.

She stares at her fingernails. “Nine thousand dollars.”

I wait for Aislin to protest that she doesn’t want it. That she’s not asking for it. But she is, so she can’t.