Under Their Skin by Margaret Peterson Haddix

shoved her brother’s T-shirt up toward his neck, so Eryn could see the boy’s long, muscular back.
    Is he choking? Eryn wondered. And they’re doing the Heimlich maneuver?
    Eryn was pretty sure it was only choking babies who needed to be pounded on the back—not anyone older than that. And anyhow, why would Ava and her mom need to raise Jackson’s shirt to hit his back?
    Jackson’s mom seemed to be just tapping his backvery deliberately, in spots she measured off by spreading her fingers and rotating her hands.
    And then it looked like Jackson’s entire back sprang open, revealing a mass of wires and circuitry inside.

TWENTY
    He’s a robot? Nick thought. Jackson’s a robot?
    He glanced toward Eryn, to see if she’d figured out the same thing. Her face was suddenly, explosively red, and her eyes had shrunk into tiny slits. Her jaw dropped.
    She’s going to scream, Nick thought.
    He clamped his hand over her mouth.
    But maybe his face looked the exact same way, because at the same time she shoved her hand over his mouth.
    For a moment they just stared at each other, bug-eyed. Then Nick lifted his other hand and pulled Eryn’s away from his mouth. She did the same to his.
    â€œKeep watching,” she whispered.
    â€œRight,” Nick whispered back.
    Jackson’s mom was pulling all sorts of wires out of his back, like she was looking for the source of his malfunction. Er—was it still right to think of her as his mom if he was just a robot?
    Or, what’s the word for a robot that’s shaped like a human? Nick tried to remember. An android? That’s not even really possible, is it? Not this good of an imitation. Aren’t androids just imaginary? Pretend?
    Nick had never been a robotics kind of kid, so he didn’t really know what was possible. He knew kids at school who were on the robotics team—but that was just about building little vehicles out of Legos and using a remote control to make them move. That wasn’t someone looking and acting and seeming like a normal sixth-grade boy who was actually totally mechanical.
    Or is he totally mechanical? Nick wondered. Isn’t there something where a person could be part human, part robot? A cyborg?
    Nick couldn’t quite remember if that was the right term or not. His own brain seemed just as stuck as Jackson’s. It was a little amazing that Nick wasn’t stammering c-c-c-can’t b-b-b-be.
    â€œHelp me turn him,” the mom was saying to Ava inside.
    She’s still a mom as long as Ava’s not an android or a cyborg or whatever, too, Nick told himself.
    The mom and Ava shifted Jackson’s body a quarter-turn, so now he had his back toward the foyer, not toward thewindow where Nick and Eryn were still spying. Then the mom pressed something on Jackson’s side that made his whole body open up. The back half of his body stayed in place; the front half sprang to the side, facing the couch and revealing all of Jackson’s innards.
    Now Nick could see into Jackson’s body head to toe, and it was like taking the back panel off a computer, or like looking inside a TV. Jackson was full of wires and circuitry and computer chips everywhere. There was no room left for a heart or a brain or lungs.
    Okaaay, Nick told himself. Definitely an android, not a cyborg.
    He was proud that he could be so analytical and rational, but he found that he’d pressed his gloved hand into his mouth—gagging himself this time, so Eryn didn’t have to do it for him. Eryn must have had the same thought; she pressed both hands over her mouth and face, only leaving the barest gap for her eyes.
    Inside, Nick noticed, Ava reacted dramatically as well, turning her head away from Jackson and shielding her eyes with her hands.
    â€œMom,” Ava said. “Mo-om, please . . .”
    The mother paused in the midst of twisting wires inside Jackson’s body.
    â€œAva, this is