"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.

As for me, I fell somewhere between my sisters and their strong personalities, the very personification of the vast gray area that separated them. I was not bold and outspoken, or silent and calculating. I had no idea how anyone would describe me, or what would come to mind at the sound of my name. I was just Annabel.

My mother, conflict-adverse herself, hated it when my sisters fought. "Why can't you just be nice?" she'd plead with them. They might have rolled their eyes, but a message sank in with me: that being nice was the ideal, the one place where people didn't get loud or so quiet they could scare you. If you could just be nice, then you wouldn't have to worry about arguments at all. But being nice wasn't as easy as it seemed, especially when the rest of the world could be so mean.

By the time I got to the snack bar, Kirsten had disappeared (of course), but the girl was still there, waiting for the guy behind the counter to ring up her candy bar. Oh well, I thought, as I walked up to her. Here goes nothing.

"Hi," I said. She just looked at me, her expression unreadable. "Urn, I'm Annabel. You just moved here, right?"

She didn't say anything for what seemed like a really long while, during which time Kirsten walked out of the ladies' room behind her. She stopped when she saw us talking.

"I," I continued, now even more uncomfortable, "I, um, think we're in the same grade."

The girl reached up, pushing her sunglasses farther up her nose. "So?" she said, in that same sharp, snide voice as the first time she'd addressed me.

"I just thought," I said, "that since, you know, we're the same age, you might want to hang out. Or something."

Another pause. Then the girl said, as if clarifying, "You want me to hang out. With you."

She made it sound so ridiculous I immediately began backtracking. "I mean, you don't have to," I told her. "It was just—"

"No," she cut me off flatly. Then she tilted her head back and laughed. "No way."

The thing is, if it had just been me there, that would have been it. I would have turned around, face flushed, and gone back to Clarke, game over. But it wasn't just me.

"Hold on," Kirsten said, her voice loud. "What did you just say?"

The girl turned around. When she saw my sister, her eyes widened. "What?" she said, and I couldn't help but notice how different this, the first word she'd ever said to me, sounded as she said it now.

"I said," Kirsten repeated, her own voice sharp, "what did you just say to her?"

Uh-oh, I thought.

"Nothing," the girl replied. "I just—"

"That's my sister," Kirsten said, pointing at me, "and you were just a total bitch to her."

By this point, I was already both cringing and blushing. Kirsten, however, put her hand on her hip, which meant she was just getting started.

"I wasn't a bitch," the girl said, taking off her sunglasses. "I only—"

"You were, and you know it," Kirsten said, cutting her off. "So you can stop denying it. And stop following me around, too, okay? You're creeping me out. Come on, Annabel."

I was frozen to the spot, just looking at the girl's face. Without her sunglasses, her expression stricken, she suddenly looked twelve, just staring at us as Kirsten grabbed my wrist, tugging me back to where she and her friends were sitting.

"Unbelievable," she kept saying, and as I looked across the pool I could see Clarke watching me, confused, as Kirsten pulled me down onto her chair. Molly sat up, blinking, reaching up to catch the untied straps of her bikini.

"What happened?" she asked, and as Kirsten began to tell her, I glanced back toward the snack bar, but the girl was gone. Then I saw her, through the fence behind me, walking across the parking lot, barefoot, her head ducked down. She'd left all her stuff on the chair beside me—a towel, her shoes, a bag with a magazine and billfold, a pink hairbrush. I kept waiting for her to realize this and turn back for it. She didn't.

Her things stayed there all afternoon: After I'd gone back to sit with Clarke, and told her everything. After we played several hands of rummy, and swam until our fingers were pruny. After Kirsten and Molly left, and other people took their chairs. All the way up until the lifeguard finally blew the whistle, announcing closing time, and Clarke and I packed up and walked around the edge of the pool, sunburned and hungry and ready to go home.

I knew this girl was not my problem. She'd been mean to me, twice, and therefore was not deserving of my pity or help. But as we passed the chair, Clarke stopped. "We can't just leave it," she said, bending over to gather up the shoes and stuff them into the bag. "And it's on our way home."

I could have argued the point, but then I thought again of her walking across the parking lot, barefoot, alone. So I pulled the towel off the chair, folding it over my own. "Yeah," I said. "Okay."

Still, when we got to the Daughtrys' old house, I was relieved to see all the windows were dark and there was no car in the driveway, so we could just leave the girl's stuff and be done with it. But as Clarke bent down to stick the bag against the front door, it opened, and there she was.

She had on cutoff shorts and a red T-shirt, her hair pulled back in a ponytail. No sunglasses. No high-heeled sandals. When she saw us, her face flushed.