From The Book of Atlantis Black, which was published last month by Tin House Books.

1.

Once, when my older sister Nancy was twelve, she told me she’d decided to run away by hopping a freight train. Her best friend, Jen, had done it. When she invited me to join her, I refused, and threatened to tell our father.

“Don’t be a wuss,” she said. She stared me down and ordered me not to say anything to anyone, even if she never came back.

She was gone for several hours. Mom had a doctor’s appointment that day but wasn’t leaving her room. I was about to wake her when Nancy came in the front door and breezed past me into the kitchen.

“Did you do it?” I called.

“Wouldn’t you like to know.”

“You couldn’t have gone that far, or you wouldn’t be back,” I said.

That night, she came into my room. She said that she never intended to go all the way to Harrisburg, or wherever that train was heading. She rode it for a few minutes, and then jumped off to spend the remainder of the afternoon in the woods with Jen. I knew, then, that she could disappear whenever she wanted, whether to scare me or to feel alive or to imagine herself gone.

2.

When Nancy was thirteen, she climbed out her window in the middle of the night and walked the nine miles to our school, through woods and fields and across Highway 1. The next day, she showed up on time for her environmental science class and took her seat near where a buck’s head hung on the wall. She told me that night-walking was a beautiful and tranquilizing experience.

3.

When we were teenagers, my sister would come into my bedroom, lie down on the floor, and start talking. She told me she believed in reincarnation, and that she was attracted to the desert because her spirit was a coyote. She asked whether I had ever experienced astral projection, and when I said I hadn’t she told me I’d have to be lying down and hovering at the edge of a dream.

4.

In 1994, my seventeen-year-old sister gave birth to a new self. For Atlantis Black to exist, she had to get rid of Eunice Anne Bonner. Two local newspapers printed the legal notice, and the people of Chadds Ford had a month to present objections. There were none. Eunice Anne Bonner drove herself to the hearing and emerged Eunice Anne Black. Later on, she forged a document to make Atlantis her middle name.

5.

In 360 bc, when Plato invented the lost island of Atlantis in his dialogues Timaeus and Critias, most readers understood that it was not a real place. But in 1882, Ignatius Donnelly, a politician from Philadelphia, published Atlantis: The Antediluvian World, a pseudoscientific account of the flora, fauna, and history of Atlantis. The Theosophists Madame Blavatsky and Rudolf Steiner expanded on the mythology and wrote about Atlanteans as a “root race” that had existed ten thousand years earlier. Blavatsky’s The Secret Doctrine described Atlanteans as godlike beings who had become human and thereby destroyed themselves. Steiner’s Atlantis and Lemuria claimed that Atlanteans existed in a kind of “dream consciousness” and valued personal experience over traditional learning: an Atlantean “did not think, he remembered.”

6.

On June 25, 2008, a young woman with my sister’s IDs was found dead on the floor of a hotel room in Tijuana. Her body had needle marks in the left arm, a wound on the right middle finger, and a bruised cranium. She wore blue jeans and a brown T-shirt that read good karma. Two syringes were in the room: one on the nightstand, one in her purse. The police report said that the IDs—including an American passport and a California driver’s license issued to “Eunice Atlantis Black”—did not appear to match the body, which was cremated without taking fingerprints or checking dental records. The autopsy report said the woman had green eyes and weighed less than one hundred pounds. It estimated that she had been twenty to twenty-five years old. My sister had hazel eyes, like my mother. She was thirty-one and running from felony charges in a prescription-drug case in California when she disappeared.

7.

The story I told to myself, to my therapist, and to my friends, was that Atlantis was dead, and that she’d killed herself in protest against the DEA. The story I kept to myself was that even if Atlantis hadn’t really died in Tijuana, she couldn’t have managed to live much longer on the run.