I fled the mountain with my bags half packed and did not retrieve anything that was left behind. I went to Salt Lake and spent the rest of the holidays with Drew.

I tried to forget that night. For the first time in fifteen years, I closed my journal and put it away. Journaling is contemplative, and I didn't want to contemplate anything.

It was early March when it happened. Shawn sent me an email. It contained no greeting, no message whatsoever. Just a chapter from the Bible, from Matthew, with a single verse set apart in bold: O generation of vipers, how can ye, being evil, speak good things? It froze my blood.

After the New Year I returned to Cambridge, but I withdrew from my friends. I had seen the earth tremble, felt the preliminary shock; now I waited for the seismic event that would transform the landsape. I knew how it would begin. Shawn would think about what Dad had told him on the phone, and sooner or later he would realize that my denial -- my claim that Dad had misunderstood me -- was a lie. When he realized the truth, he would despise himself for perhaps an hour. Then he would transfer his loathing to me.

"I can't decide," he said. He paused, and I thought perhaps the connection had failed. "Whether I should kill you myself, or hire an assassin." There was a static-filled silence. "It might be cheaper to hire someone, when you figure in the cost of the flight."

Shawn called an hour later. His tone was casual, and we talked for twenty minutes about Peter, about how his lungs were developing. Then he said, "I have a decision to make, and I'd like your advice."

"Sure."

I pretended I hadn't understood, but this only made him aggressive. Now he was hurling insults, snarling. I tried to calm him but it was pointless. We were seeing each other at long last. I hung up on him but he called again, and again and again, each time repeating the same lines, that I should watch my back, that his assassin was coming for me. I called my parents.

"He didn't mean it," Mother said. "Anyway, he doesn't have that kind of money."

"Not the point," I said.

Dad wanted evidence. "You didn't record the call?" he said. "How am I supposed to know if he was serious?"

The phone calls stopped, eventually, but not because of anything my parents did. They stopped when Shawn cut me out of his life. He wrote, telling me to stay away from his wife and child, and to stay the hell away from him. The email was long, a thousand words of accusation and bile, but by the end his tone was mournful. He said he loved his brothers, that they were the best men he knew. I loved you the best of all of them, he wrote, but you had a knife in my back the whole time.

"Well, he wasn't serious about that."

"Not the point," I said again.

"He sounded like he did when he threatened me with the bloody knife," I said.

It had been years since I'd had a relationship with my brother, but the loss of it, even with months of foreknowledge, stunned me.

My parents said he was justified in cutting me off. Dad said I was hysterical, that I'd thrown thoughtless accusations when it was obvious my memory couldn't be trusted. Mother said my rage was a real threat and that Shawn had a right to protect his family. "Your anger that night," she told me on the phone, meaning the night Shawn had killed Diego, "was twice as dangerous as Shawn has ever been."

I agreed. It was exactly like that.

"Talking to you," she said, "your reality is so warped. It's like talking to someone who wasn't even there."

Reality became fluid. The ground gave way beneath my feet, dragging me downward, spinning fast, like sand rushing through a hole in the bottom of the universe. The next time we spoke, Mother told me that the knife had never been meant as a threat. "Shawn was trying to make you more comfortable," she said. "He knew you'd be scared if he were holding a knife, so he gave it to you." A week later she said there had never been any knife at all.

I had a grant to study that summer in Paris. Drew came with me. Our flat was in the sixth arrondissement, near the Luxembourg Gardens. My life there was entirely new, and as near to a cliché as I could make it. I was drawn to those parts of the city where one could find the most tourists so I could throw myself into their center. It was a hectic form of forgetting, and I spent the summer in pursuit of it: of losing myself in swarms of travelers, allowing myself to be wiped clean of all personality and character, of all history. The more crass the attraction, the more I was drawn to it.

My father had visited her -- this I understood immediately -- but I had to read the message several times before I understood what exactly had taken place. Our father had testified to her that Shawn had been cleansed by the Atonement of Christ, that he was a new man. Dad had warned Audrey that if she ever again brought up the past, it would destroy our entire family. It was God's will that Audrey and I forgive Shawn, Dad said. If we did not, ours would be the greater sin.

I had been in Paris for several weeks when, one afternoon, returning from a French lesson, I stopped at a café to check my email. There was a message from my sister.

I could easily imagine this meeting, the gravity of my father as he sat across from my sister, the reverence and power in his words.

Audrey told Dad that she had accepted the power of the Atonement long ago, and had forgiven her brother. She said that I had provoked her, had stirred up anger in her. That I had betrayed her because I'd given myself over to fear, the realm of Satan, rather than walking in faith with God. I was dangerous, she said, because I was controlled by that fear, and by the Father of Fear, Lucifer.

There was little hope of overpowering the history my father and sister were creating for me. Their account would claim my brothers first, then it would spread to my aunts, uncles, cousins, the whole valley. I had lost an entire kinship, and for what?

That is how my sister ended her letter, by telling me I was not welcome in her home, or even to call her unless someone else was on the line to supervise, to keep her from succumbing to my influence. When I read this, I laughed out loud. The situation was perverse but not without irony: a few months before, Audrey had said that Shawn should be supervised around children. Now, after our efforts, the one who would be supervised was me.

I knew my father would pay my brothers the same visit he'd paid her. Would they believe him? I thought they would. After all, Audrey would confirm it. My denials would be meaningless, the rantings of a stranger. I'd wandered too far, changed too much, bore too little resemblance to the scabby-kneed girl they remembered as their sister.

When i lost my sister, I lost my family.

After I read Audrey's letter, the past shifted. It started with my memories of her. They transformed. When I recalled any part of our childhood together, moments of tenderness or humor, of the little girl who had been me with the little girl who had been her, the memory was immediately changed, blemished, turned to rot. The past became as ghastly as the present.

It was in this state of mind that I received another letter: I had won a visiting fellowship to Harvard. I don't think I have ever received a piece of news with more indifference. I knew I should be drunk with gratitude that I, an ignorant girl who'd crawled out of a scrap heap, should be allowed to study there, but I couldn't summon the fervor. I had begun to conceive of what my education might cost me, and I had begun to resent it.

The change was repeated with every member of my family. My memories of them became ominous, indicting. The female child in them, who had been me, stopped being a child and became something else, something threatening and ruthless, something that would consume them.

My journals were a problem. I knew that my memories were not memories only, that I had recorded them, that they existed in black and white. This meant that more than my memory was in error. The delusion was deeper, in the core of my mind, which invented in the very moment of occurrence, then recorded the fiction.

I began to defer, always, to the judgment of others. If Drew remembered something differently than I did, I would immediately concede the point. I began to rely on Drew to tell me the facts of our lives. I took pleasure in doubting myself about whether we'd seen a particular friend last week or the week before, or whether our favorite crêperie was next to the library or the museum. Questioning these trivial facts, and my ability to grasp them, allowed me to doubt whether anything I remembered had happened at all.

This monster child stalked me for a month before I found a logic to banish her: that I was likely insane. If I was insane, everything could be made to make sense. If I was sane, nothing could. This logic seemed damning. It was also a relief. I was not evil; I was clinical.

In the month that followed, I lived the life of a lunatic. Seeing sunshine, I suspected rain. I felt a relentless desire to ask people to verify whether they were seeing what I was seeing. Is this book blue? I wanted to ask. Is that man tall?

In those moments I searched feverishly for a reason to think myself sane. Evidence. I craved it like air. I wrote to Erin -- the woman Shawn had dated before and after Sadie, who I hadn't seen since I was sixteen. I told her what I remembered and asked her, bluntly, if I was deranged. She replied immediately that I was not. To help me trust myself, she shared her memories -- of Shawn screaming at her that she was a whore. My mind snagged on that word. I had not told her that that was my word.

Sometimes this skepticism took the form of uncompromising certainty: there were days when the more I doubted my own sanity, the more violently I defended my own memories, my own "truth," as the only truth possible. Shawn was violent, dangerous, and my father was his protector. I couldn't bear to hear any other opinion on the subject.

While traveling in Utah for research, I would meet a young man who would bristle at my last name.

Erin told me another story. Once, when she had talked back to Shawn -- just a little, she said, as if her manners were on trial -- he'd ripped her from her house and slammed her head against a brick wall so hard she'd thought he was going to kill her. His hands locked around her throat. I was lucky, she wrote. I had screamed before he began choking me, and my grandpa heard it and stopped him in time. But I know what I saw in his eyes.

Her letter was like a handrail fixed to reality, one I could reach out and grasp when my mind began to spin. That is, until it occurred to me that she might be as crazy as I was. She was damaged, obviously, I told myself. How could I trust her account after what she'd been through? I could not give this woman credence because I, of all people, knew how crippling her psychological injuries were. So I continued searching for testimony from some other source.

Four years later, by pure chance, I would get it.

"Well, the last time I saw your brother," he would say, emphasizing this last word as if he were spitting on it, "he had both hands wrapped around my cousin's neck, and he was smashing her head into a brick wall. He would have killed her, if it weren't for my grandfather."

"Westover," he would say, his face darkening. "Any relation to Shawn?"

"My brother."

And there it was. A witness. An impartial account. But by the time I heard it, I no longer needed to hear it. The fever of self-doubt had broken long ago. That's not to say I trusted my memory absolutely, but I trusted it as much as I trusted anybody else's, and more than some people's.

But that was years away.