I’d never make it on the bus.”
“It’s not important,” she said.
Before she walked out the door, I gave her our traditional half salute. For two seconds, maybe three, I heard the familiar sounds of the outside world infiltrating our quiet house—a car passing, a kid riding a skateboard down the steep sidewalk, a snatch of music from an open window across the street. Then the front door clicked softly behind her, and she was gone. In the months to follow, when I recalled that moment, I would suspect that the clicking sound I’d heard wasn’t the door, but something in my own mind, some barely audible psychic signal. I would tell myself that if only I had listened, if only I had paid attention, I could have somehow changed the story.
That night, I passed Lila’s message on to our parents, and we all went to bed as usual. The next morning, when I came downstairs, my mother stood at the kitchen counter eating cereal and perusing a legal brief, while my father sat at the table with his newspaper and buttered toast. “Go wake your sister, Ellie,” my mother said. “I can’t believe she’s not up. She has a nine-o’clock class.”
I went upstairs and knocked on her door, but she didn’t answer. I opened the door and saw that her bed was undisturbed, the white pillow shams and coverlet pristine. The small bathroom we shared was attached to my room, and Lila always listened to KLIV while getting ready in the morning. There was no way she could have showered and dressed without my hearing her.
I went downstairs. My mother was rinsing her cereal bowl in the sink. “She’s not here,” I said. “It looks like she didn’t come home last night.”
My mother turned to face me, her hands still wet. “What?”
My father looked up from his paper, startled. “She didn’t call?”
“Did she tell you where she was going last night?” my mother asked.
“No. She was upset yesterday morning, but she wouldn’t say why.”
“This person she’s been seeing,” my mother said to me. “Do you know who he is?”
“She won’t tell me anything.”
I went up to her room and retrieved her schedule from the bulletin board above her desk. We called the office of the Stanford Journal of Mathematics, where she worked part-time. She hadn’t been at her five-o’clock meeting the night before. “Weird,” the editor said. “It’s the first meeting she’s missed in two years.” Next, we called a guy named Steve who led a seven p.m. study group Lila was in; she had also missed the study group.
At that point, my father called the police and filed a missing person report. An officer came to our house and asked for a photograph of Lila, which he slid into a plastic sleeve. After he left, we went into the living room and waited for the phone to ring. That was Thursday. For two days there was no trace of her. It was as if my sister had walked to the Greyhound station, bought a ticket to Somewhere Else, and vanished.
On Saturday of that week Lila’s backpack was found in a Dumpster in Healdsburg. It still contained her wallet, her house keys, and her books. The only thing missing was a perfect-bound notebook, about an inch thick, with a blue plaid cover. I knew the notebook would have been in her backpack when she left home because she never went anywhere without it. It wasn’t a journal in the traditional sense. Instead of words, it contained numbers, page after page of formulae. For me, trying to read one of her calculations was akin to saying an ordinary word as fast as possible a dozen times in a row; the numbers and letters, taken separately, each looked familiar, but grouped together so densely they seemed mysterious, like some alien code that only a savant could crack. While I immersed myself in indie music and Eastern European novels, Lila filled her time with equations and algorithms, long sequences of letters and numerals stretching across and down the graph-paper pages.
“What’s all this?” I had asked