You could figure out, if you had the inclination and the time, who in a given year was friends with whom and who had dated whom, and who had been popular, or athletic, or weird and fringy. The graduated students began to feel like distant cousins-I learned their nicknames, their sports of choice, which sweater or hairstyle they’d worn on repeated occasions.

In the three most recent yearbooks, I found several photos of Gates. She played field hockey, basketball, and lacrosse, and she’d lived her freshman and sophomore years in Elwyn’s dorm and her junior year in Jackson’s. Her sophomore year, the little joke about her was, “The crystal ball predicts that Henry and Gates will buy a house with a white picket fence and have twelve kids.” The only Henry at Ault was Henry Thorpe, who I knew was currently going out with a prissy-seeming sophomore named Molly. I wondered if Henry and Gates had really dated and, if so, whether any tension of either the good or bad sort lingered between them. When they danced together at roll call, it had not seemed like it.

It was at the end of the yearbook from Gates’s junior year, which was the newest one, that I came across the picture. The final section, after the seniors’ pages, contained photos of graduation: the senior girls in white dresses, the boys in white pants and navy blazers and boaters. There were pictures of them sitting in rows at the ceremony, a picture of the graduation speaker (a Supreme Court justice), pictures of the seniors hugging each other. Among these-I was not looking for her here and might easily have missed it-was one of Gates by herself. It showed her from the waist up, in a white short-sleeved button-down. She wore a cowboy hat, and her glinting hair fell out from under the brim and spilled over her shoulders. The picture would have been in profile, but it appeared that the photographer, whoever it was, had called her name just before snapping the shutter and she’d turned her head. She might have been simultaneously laughing and protesting, saying something like, Oh, come on! But saying it to a person she liked very much.

I stared at the picture for so long that when I looked up again, I was surprised to see the nubbly orange couches and cream-colored walls of the common room. I had forgotten myself, and I had forgotten Ault, at least the real, three-dimensional version in which I, too, was a presence. It was a little after ten. I decided to check in early with Madame and go to bed, and I put the yearbooks away.

In the upstairs bathroom, Little stood before one of the sinks in a pink bathrobe, rubbing oil through her hair.

“Hey,” I said. “How was the dance?”

She made a face. “I wouldn’t go to no drag dance.”

“Why not?”

“Why didn’t you go?”

I smiled, and then she smiled, too.

“See?” she said. “But your roommate sure was excited about it. If I lived with that girl, I’d have slapped her by now.”

“She’s not that bad.”

“Uh-huh.”

“You play varsity basketball, right?” I said.

“Yep.”

“So you’re on the team with Gates Medkowski, right?”

“Sure am.”

“What’s Gates like? I’m just wondering because she’s the first girl ever to be a senior prefect, isn’t she? I know that’s a pretty big deal.”

“She’s about like everyone else here.”

“Really? She seems different.”

Little set the bottle of oil on the counter and leaned in close to the mirror, peering at her skin. Then she said, “She’s rich. That’s what Gates is. Her family has a whole lot of money.” She stepped back and made a face in the mirror, sucking in her cheeks and arching her eyebrows. It was the kind of thing I’d have done alone but never in front of another person. But I kind of liked the fact that Little’s attention to me was sporadic; it made me feel less inhibited.

“I thought Gates was from a farm,” I said.

“A farm that’s half the state of Idaho. Her people grow potatoes. Bet you didn’t think such a nasty little vegetable could be worth so much.”

“Is Gates good at basketball?”

“Not as good as me.” In the mirror, Little grinned. “You ever find out about my name?”

“Not yet,” I said. “I’m conducting an investigation, but all my leads have been dead ends.”

“Yeah, right. I’ll tell you why. It’s because I’m a twin.”

“For real?”

“Yep. I’m the baby, so you can guess my sister’s name.” She was quiet, and I realized I really was supposed to guess.

“This might be too obvious, but is it Big?”

“Got it on the first try,” Little said. “Give the girl a prize. I’m bigger than Big now, but these things stick.”

“That’s really cool,” I said. “Where does Big go to school?”

“At home. Pittsburgh. You ever been to Pittsburgh?”

I shook my head.

“It’s different from here, I’ll tell you that much.”

“You must miss Big.” Knowing Little had a twin, even a twin who was far away, made me wonder if she didn’t need a friend.

“You got any sisters?” Little asked.

“Just brothers.”

“Yeah, I got a brother, too. I got three brothers. But that’s not the same.” She stuck her bottle of oil into her bucket-on the first night in the dorm, Madame Broussard had given us all buckets for our toiletries-and turned toward me. “You’re not bad,” she said. “Most people here, they’re not real. But you’re real.”

“Oh,” I said. “Thanks.”

When she was gone-on the way out, she said, “G’nighty”-I pulled my toothbrush and toothpaste from my own bucket. When I stuck my toothbrush under the faucet, I noticed that in the sink next to mine, the one where Little had been standing, there was a sprinkling of short, coarse black hairs. So they were head hairs, Little’s head hairs. With a paper towel from the dispenser, I wiped them away.

The next theft was a hundred-dollar bill Aspeth’s grandmother had sent for her birthday. It had been in her wallet, which had been on top of her desk. We found out on Sunday, the night after the drag dance. I learned the amount and the owner of the money not from anything Madame Broussard said at curfew-again, she was stony-faced and discreet-but from Dede, who was outraged.

“It’s like my friends and I are targets,” Dede said when we were back in our room. “We’re being discriminated against.” She leaned over and set a red cashmere sweater on the floor, on top of black pants. When she was upright again, she wrinkled her nose. “Something stinks in here.”

I sniffed the air, but I was pretending. She was right-it did stink. It had stunk for several days, and at first I’d thought I was imagining the fishy odor, but it had become more pronounced. When Dede and Sin-Jun were out of the room, I’d smelled my armpits and between my legs, then my sheets, then my dirty laundry. The fishiness hadn’t increased in any of these places, but it hadn’t decreased either. “It does smell kind of weird,” I said.

“Hey, Sin-Jun,” Dede said. “Take a whiff. It smells bad, right?”

“Take a whiff?”

“Smell the air,” I said. I mimed inhaling deeply. “Our room smells funny,” I said. “Not so good.”

“Ahh,” Sin-Jun said. She turned back to the papers on her desk.

Dede rolled her eyes at me.

“Maybe it’s coming from the bathroom,” I said. This seemed unlikely.

Dede opened the door to our room and stepped into the hallway. Then she walked back in. “No, it’s this room,” she said. “It’s definitely this room. What food do you guys have in here?”

“Only that.” I gestured toward the shelf above my desk, where I kept a jar of peanut butter and a box of saltines.

“What about you, Sin-Jun?” Dede said.

Before Sin-Jun could respond, I said, “Why are you assuming it’s us? It might be you.”

“I’m not the one keeping an entire grocery store in here,” Dede said, and it was true that Sin-Jun had several packages and containers beneath her bed and in her desk and closet.

“But you don’t know that it’s food,” I said. “Maybe it’s your shoes.” I picked up my bucket.