"The PhD is exceptionally demanding," he said. "It's okay if you can't do it."

If I had explained to my supervisor, Dr. Runciman, why I was unable to work, he would have helped me, would have secured additional funding, petitioned the department for more time. But I didn't explain, I couldn't. He had no idea why it had been nearly a year since I'd sent him work, so when we met in his office one overcast July afternoon, he suggested that I quit.

I was failing my PhD.

I left his office full of fury at myself. I went to the library and gathered half a dozen books, which I lugged to my room and arranged on my desk. But my mind was made nauseous by rational thought, and by the next morning the books had moved to my bed, where they propped up my laptop while I worked steadily through Buffy the Vampire Slayer.

That autumn, Tyler confronted my father. He talked to Mother first, on the phone. He called me after and related their conversation. He said Mother was "on our side," that she thought the situation with Shawn was unacceptable and had convinced Dad to do something. "Dad is taking care of it," Tyler said. "Everything is going to be fine. You can come home."

I listened to Tyler relate this story while staring at the frozen image of Sarah Michelle Gellar. Tyler talked for a long time, moving through the events quickly but lingering in a wasteland of rationalization and self-recrimination. Dad must have misunderstood, Tyler said. There had been a mistake, a miscommunication. Maybe it was his fault, maybe he hadn't said the right thing in the right way. That was it. He had done this, and he could repair it.

Tyler was still reeling from Dad's threat when his phone rang. He thought it was Dad calling to apologize, but it was Shawn. Dad had told him everything. "I can have you out of this family in two minutes," Shawn said. "You know I can do it. Just ask Tara."

I dislike imagining this conversation. Tyler's stutter was always worse when he talked to our father. I picture my brother hunched over the receiver, trying to concentrate, to push out the words that have jammed in his throat, while his father hurls an arsenal of ugly words.

My phone rang again two days later, and I paused Buffy to answer it. It was Tyler. The whole thing had exploded in his face. He had felt uneasy after his conversation with Mother, so he had called Dad to see exactly what was being done about Shawn. Dad had become angry, aggressive. He'd shouted at Tyler that if he brought this up again, he would be disowned, then he'd hung up the phone.

It was October when I got the letter.

So I knew even before it happened that Tyler would go the same way. I could hear his hand-wringing through the long echo of the telephone. He was deciding what to do, but I knew something he did not: that the decision had already been made, and what he was doing now was just the long work of justifying it.

As I listened, I felt a strange sensation of distance that bordered on disinterestedness, as if my future with Tyler, this brother I had known and loved all my life, was a film I had already seen and knew the ending of. I knew the shape of this drama because I had lived it already, with my sister. This was the moment I had lost Audrey: this was the moment the costs had become real, when the tax was levied, the rent due. This was the moment she had realized how much easier it was to walk away: what a poor trade it was to swap an entire family for a single sister.

It came in the form of a PDF attached to an email from Tyler and Stefanie. The message explained that the letter had been drafted carefully, thoughtfully, and that a copy would be sent to my parents. When I saw that, I knew what it meant. It meant Tyler was ready to denounce me, to say my father's words, that I was possessed, dangerous. The letter was a kind of voucher, a pass that would admit him back into the family.

When I heard this story, I made the only good decision I had made for months: I enrolled in the university counseling service. I was assigned to a sprightly middle-aged woman with tight curls and sharp eyes, who rarely spoke in our sessions, preferring to let me talk it out, which I did, week after week, month after month. The counseling did nothing at first -- I can't think of a single session I would describe as "helpful"-- but their collective power over time was undeniable. I didn't understand it then, and I don't understand it now, but there was something nourishing in setting aside that time each week, in the act of admitting that I needed something I could not provide for myself.

I clicked the mouse, the attachment opened. I was so far removed from myself that I read the entire letter without understanding it: Our parents are held down by chains of abuse, manipulation, and control… They see change as dangerous and will exile anyone who asks for it. This is a perverted idea of family loyalty… They claim faith, but this is not what the gospel teaches. Keep safe. We love you.

From Tyler's wife, Stefanie, I would learn the story of this letter, how in the days after my father had threatened disownment, Tyler had gone to bed every night saying aloud to himself, over and over, "What am I supposed to do? She's my sister."

I couldn't get myself to open the attachment; some instinct had seized my fingers. I remembered Tyler as he'd been when I was young, the quiet older brother reading his books while I lay under his desk, staring at his socks and breathing in his music. I wasn't sure I could bear it, to hear those words in his voice.

Tyler did send the letter to my parents, and once committed he never wavered. That winter I spent many hours on the phone with him and Stefanie, who became a sister to me. They were available whenever I needed to talk, and back then I needed to talk quite a lot.

I've apologized to Tyler more times than I can count for what I've cost him, but the words are awkwardly placed and I stumble over them. What is the proper arrangement of words? How do you craft an apology for weakening someone's ties to his father, to his family? Perhaps there aren't words for that. How do you thank a brother who refused to let you go, who seized your hand and wrenched you upward, just as you had decided to stop kicking and sink? There aren't words for that, either.

Tyler paid a price for that letter, though the price is hard to define. He was not disowned, or at least his disownment was not permanent. Eventually he worked out a truce with my father, but their relationship may never be the same.

Winter was long that year, the dreariness punctuated only by my weekly counseling sessions and the odd sense of loss, almost bereavement, I felt whenever I finished one TV series and had to find another.

Then it was spring, then summer, and finally as summer turned to fall, I found I could read with focus. I could hold thoughts in my head besides anger and self-accusation. I returned to the chapter I had written nearly two years before at Harvard. Again I read Hume, Rousseau, Smith, Godwin, Wollstonecraft and Mill. Again I thought about the family. There was a puzzle in it, something unresolved. What is a person to do, I asked, when their obligations to their family conflict with other obligations -- to friends, to society, to themselves?

The chapter on Mormonism was my favorite. As a child in Sunday school, I'd been taught that all history was a preparation for Mormonism: that every event since the death of Christ had been fashioned by God to make possible the moment when Joseph Smith would kneel in the Sacred Grove and God would restore the one true church. Wars, migrations, natural disasters -- these were mere preludes to the Mormon story. On the other hand, secular histories tended to overlook spiritual movements like Mormonism altogether.

I began the research. I narrowed the question, made it academic, specific. In the end, I chose four intellectual movements from the nineteenth century and examined how they had struggled with the question of family obligation. One of the movements I chose was nineteenth-century Mormonism. I worked for a solid year, and at the end of it I had a draft of my thesis: "The Family, Morality, and Social Science in Anglo-American Cooperative Thought, 1813-1890."

As I walked home carrying the heavy manuscript, I remembered attending one of Dr. Kerry's lectures, which he had begun by writing, "Who writes history?" on the blackboard. I remembered how strange the question had seemed to me then. My idea of a historian was not human; it was of someone like my father, more prophet than man, whose visions of the past, like those of the future, could not be questioned, or even augmented. Now, as I passed through King's College, in the shadow of the enormous chapel, my old diffidence seemed almost funny. Who writes history? I thought. I do.

My dissertation gave a different shape to history, one that was neither Mormon nor anti-Mormon, neither spiritual nor profane. It didn't treat Mormonism as the objective of human history, but neither did it discount the contribution Mormonism had made in grappling with the questions of the age. Instead, it treated the Mormon ideology as a chapter in the larger human story. In my account, history did not set Mormons apart from the rest of the human family; it bound them to it.

I sent Dr. Runciman the draft, and a few days later we met in his office. He sat across from me and, with a look of astonishment, said it was good. "Some parts of it are very good," he said. He was smiling now. "I'll be surprised if it doesn't earn a doctorate."

I had built a new life, and it was a happy one, but I felt a sense of loss that went beyond family. I had lost Buck's Peak, not by leaving but by leaving silently. I had retreated, fled across an ocean and allowed my father to tell my story for me, to define me to everyone I had ever known. I had conceded too much ground -- not just the mountain, but the entire province of our shared history.

On my twenty-seventh birthday, the birthday I had chosen, I submitted my PhD dissertation. The defense took place in December, in a small, simply furnished room. I passed and returned to London, where Drew had a job and we'd rented a flat. In January, nearly ten years to the day since I'd set foot in my first classroom at BYU, I received confirmation from the University of Cambridge: I was Dr. Westover.

It was time to go home.