“There might be more ways,” I said, “when we read all the books.” And Ruth nodded earnestly, making the branch sway under her. “You can use tongs, and hold the changeling in a fire.” Down below, a group of older boys were passing, wearing football uniforms from the high school, kicking dirt up, and shouting at each other in the ringing, amorphous way of teenagers. I watched as they strayed close to our backpacks, glaring and wondering if they could see me.

“Or you can beat them with a switch, I read.” I wasn’t sure what a switch was. Something like a whip, I guessed. “Until they give up and leave, or they die.”

“Hey!” one of the boys barked. “Hey!”

The branch bobbed as Ruth turned to look at them too, balancing herself with a hand splayed on the bark.

“How old are you?” he shouted. It was the boy in front, tall and big, carrying himself with the mysterious self-assurance of a high schooler. I couldn’t have guessed how old he was. He looked, to me, twenty-five.

“Eleven!” I shouted back. His foot was close to my backpack, and I was mostly worried about this. If he kicked it over, there would be dirt on the library books, and he might well kick it over by accident, but I knew enough of the boys in my own grade that it seemed more dangerous to alert him to it, make it a weakness.

“Not you!” the boy next to him yelled, his voice ringing up the hill. “You.” From where we were, and how close we were together, it was hard to be sure which of us he was shouting at, but, presumably, Ruth. “How old are you?”

“Ten!” Ruth called back to him.

“Shit!” the first boy exclaimed, turning away as if we’d disgusted him. “Shit! Ten!”

They went on then, knocking over my backpack but not seeming to mean to, and both of us watched the prickly backs of their necks, like the backs of warthogs, until they were gone. Later, it would be the same, despite the solemn effort Ruth made that summer to hide the shape of her body. Later, her age would be a less effective ward. I studied her, her eyes and the roundness of her cheeks, the places where sweat had smeared with dirt on her face, and wondered how they’d ever thought she was older than me.

“My mom has a fireplace,” Ruth said, “but I don’t think we have any switches.”

* * *

The books gave us other ways, which seemed more manageable. Though my mother had seen us come through the living room, holding our dusty backpacks in front of our chests to try to manage the weight, we still hid the books in my room; in my pillowcase, behind the science kits that lined the top shelf of my closet. We read them after bedtime, both of us lying on our stomachs, on the cooling wood floor in front of my night-light, mouthing words by the glow. Ruth fell asleep, her cheek pressing against my shoulder, and I stroked her back, where her flesh caved inward toward her spine. How could either of us need siblings, having this?