Under Their Skin by Margaret Peterson Haddix

Cohen’s driveway and sidewalk.
    Then he remembered that they’d left their shovels back at Ava and Jackson’s house. At the robots’ house.
    â€œOh no—our shovels!” he said.
    Eryn looked down at her hands like she was surprised not to still be clutching her shovel handle.
    â€œWho cares?” she said, shrugging. “We already told Mom we were at Ava and Jackson’s house. We don’t need a cover story anymore. It’s not like the shovels being under that tree are going to ruin anything.” Her face took on the set, stubborn expression that always meant she’d made up her mind. “ I’m not going back for them.”
    There was no way Nick wanted to go back either. But he was a little shocked. Mom and Dad had always drilled into them that they needed to take good care of their possessions. He could hear Mom’s voice in his mind: It’s a part of being a good steward of the Earth’s resources—and of your own resources. . . .
    He and Eryn were just breaking rules right and left today. Where would it end?
    They came into view of their own house. The driveway was mostly covered again; the snow and the wind had erased practically every sign that Nick and Eryn had ever shoveled. There were also no tire tracks in the snow, no interruption in the drifts blown against the garage door.So Nick knew neither Mom nor Michael were home yet.
    Oh no—how will we ever face Michael again? Nick wondered. How could he ever face us again?
    Maybe they wouldn’t have to. Maybe Mom would just quietly divorce Michael for lying, and they’d never have to see him again.
    Eryn started taking long steps across the yard, even as she fumbled in her pocket for the house key. His legs ached and his muscles protested, but Nick forced himself to catch up to his sister.
    Her hands shook as she tried to put the key in the keyhole.
    â€œHere,” Nick said, putting his hand over hers, helping out.
    But maybe his hands were shaking too. Or maybe some sort of ice crystals had formed inside the lock, blocking the key. Because he couldn’t get the key to work right either.
    Suddenly the door swung open and there was Mom, dressed half in her work clothes (silky red blouse, black pants) and half in gear that would be appropriate in a blizzard (fur-lined boots and a parka.)
    â€œM-mom?” Eryn stammered. “We didn’t see your car. Or any sign of it. We thought—”
    â€œI walked,” Mom said. “I left my car in a parking lot off Apple Tree Boulevard and I walked.”
    Nick braced himself for Mom to start yelling at them. He braced himself for Eryn to start yelling back.
    Instead, Mom left the door hanging open and stepped out onto the porch with them. And then she gathered them both into a massive hug, holding them tight against her parka and not letting go.
    This definitely wasn’t the way she usually hugged them when they’d done something wrong and she wanted to punish them. This was a new kind of hug, one Nick had never even had to imagine before.
    This, Nick thought, is how you hug someone you thought you’d never see again.

TWENTY-THREE
    Mom’s flipping out, Eryn thought.
    That was strange, because Mom never flipped out. She was a rock, a pillar of strength, the person you’d want beside you in any emergency. One time when Nick and Eryn were little, another kid had pushed Nick off the climbing structure at the playground. And Mom had managed to pull out all the mulch from the cuts on Nick’s knees and elbows and scrub awayall the blood and bandage all the wounds even as she calmly lectured the other kid about the importance of playing nice and being kind to other people and treating others as we ourselves would like to be treated.
    And that was while both Nick and Eryn were screaming at the top of their lungs—Nick, because he was hurt, and Eryn, because she was worried about Nick.
    So why was Mom acting