"So," my mother said one night at dinner, "I heard a new family's moved in to the Daughtrys' house, over on Sycamore."

"The Daughtrys moved?" my father asked.

My mother nodded. "Back in June. To Toledo. Remember?"

My father thought for a second. "Right," he said finally, nodding. "Toledo."

"I also heard," my mom continued, passing the bowl of pasta she was holding to Whitney, who immediately passed it on to me, "that they have a daughter your age, Annabel. I think I saw her the other day when I was over at Margie's."

"Really," I said.

She nodded. "She has dark hair, a bit taller than you. Maybe you've seen her around the neighborhood."

I thought for a second. "I don't know—"

"That's who that is!" Kirsten said suddenly. She put down her fork with a clank. "The stalker from the pool. Oh my God, I knew she had to be way younger than us."

"Hold on." Now my father was paying attention. "There's a stalker at the pool?"

"I hope not," my mother said, in her worried voice.

"She's not a stalker, really," Kirsten said. "She's just this girl who's been hanging around us. It's so creepy. She, like, sits beside us, and follows us around, and doesn't talk, and she's always listening to what we're saying. I've told her to get lost, but she just ignores me. God! I can't believe she's only twelve. That makes it even sicker."

"So dramatic," Whitney muttered, spearing a piece of lettuce with her fork.

She was right, of course. Kirsten was our resident drama queen. Her emotions were always at full throttle, as was her mouth; she never stopped talking, even if she was well aware you weren't listening to her. In contrast, Whitney was the silent type, which meant the few words she uttered always carried that much more meaning.

"Kirsten," my mother said now, "be nice."

"Mom, I've tried that. But if you saw her, you'd understand. It's strange."

My mother took a sip of her wine. "Moving to a new place is difficult, you know. Maybe she doesn't know how to make friends—"

"She obviously doesn't," Kirsten told her.

"—which means that it might be your job to meet her halfway," my mother finished.

"She's twelve," Kirsten said, as if this was on par with being diseased, or on fire.

"So is your sister," my father pointed out.

Kirsten picked up her fork and pointed it at him. "Exactly," she said.

Beside me, Whitney snorted. But my mom, of course, was already turning her attention on me. "Well, Annabel," she said, "maybe you could make an effort, if you do see her. To say hello or something."

I didn't tell my mother I'd already met this new girl, mostly because she would have been horrified she'd been so rude to me. Not that this would have changed her expectations for my behavior. My mother was famously polite, and expected the same of us, regardless of the circumstances. Our whole lives were supposed to be the high road. "Okay," I said. "Maybe I will."

"Good girl," she said. And that, I hoped, was that.

The next afternoon, though, when Clarke and I got to the pool, Kirsten was already there, lying out with Molly on one side and the new girl on the other. I tried to ignore this as we got settled in our spot, but eventually I glanced over to see Kirsten watching me. When she got up a moment later, shooting me a look, then headed toward the snack bar, the new girl immediately following her, I knew what I had to do.

"I'll back in a second," I told Clarke, who was reading a Stephen King novel and blowing her nose.

"Okay," she said.

I got up, then started around by the high dive, crossing my arms over my chest as I passed Chris Pennington. He was lying on a beach chair, a towel over his eyes, while a couple of his buddies wrestled on the pool deck. Now, instead of sneaking glances at him—which, other than swimming and getting beaten at cards, was my main activity at the pool that summer—I'd get bitched out again, all because my mother was insistent we be raised as the best of Good Samaritans. Great.

I could have told Kirsten about my previous run-in with this girl, but I knew better. Unlike me, she did not shy away from confrontation—if anything, she sped toward it, before overtaking it completely. She was the family powder keg, and I had lost track of the number of times I'd stood off to the side, cringing and blushing, while she made her various displeasures clear to salespeople, other drivers, or various ex-boyfriends. I loved her, but the truth was, she made me nervous.

Whitney, in contrast, was a silent fumer. She'd never tell you when she was mad. You just knew, by the expression on her face, the steely narrowing of her eyes, the heavy, enunciated sighs that could be so belittling that words, any words, seemed preferable to them. When she and Kirsten fought— which, with two years between them, was fairly often—it always seemed at first like a one-sided argument, since all you could hear was Kirsten endlessly listing accusations and slights. Pay more attention, though, and you'd notice Whitney's stony, heavy silences, as well as the rebuttals she offered, few as they were, that always cut to the point much more harshly than Kirsten's swirling, whirly commentaries.

One open, one closed. It was no wonder that the first image that came to mind when I thought of either of my sisters was a door. With Kirsten, it was the front one to our house, through which she was always coming in or out, usually in mid-sentence, a gaggle of friends trailing behind her. Whitney's was the one to her bedroom, which she preferred to keep shut between her and the rest of us, always.