Excerpted from The Letter: My Journey Through Love, Loss and Life by Marie Tillman (Grand Central Publishing). © 2012 by Marie Tillman. All rights reserved.

On April 22, 2004, I was in my office in Seattle, talking with a colleague about whether we should go for drinks, when the receptionist leaned into my work space. His gaze fell to the ground. I'll never forget the pause as he searched for words. "Marie? There are some people here to see you."

I didn't ask who they were. Maybe I was trying to spare myself, take a few more moments before the inevitable. I left for the conference room to find a chaplain and three soldiers standing in full-dress Army uniforms, and I knew instantly that my husband, former football player Pat Tillman, had been killed. He had been in Afghanistan for less than three weeks. I was a widow at 27.

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It wasn't really logical for Pat to leave his NFL career with the Arizona Cardinals and enlist in the Army a few months before our wedding; his decision was emotional. Since 9/11, he'd talked about wanting to defend our country. Courage was in his DNA, passed down from his grandfather, who had been at Pearl Harbor. We'd already been a couple for nearly a decade - we had known each other since we were kids in a small town south of San Francisco - and we wanted to start a family as soon as possible. His enlisting interfered with that plan. In my angry moments, I felt he was being selfish. But deep down, I knew that by asking him not to go, I'd be asking him to be someone he wasn't. Plus, I didn't really think he could get hurt or killed. He was smart and strong; he'd figure out a way to get through. I told myself that the three years of his enlistment would be a blip in our life together. I could imagine us old, sitting in our rockers, reminiscing: "Remember when you were in the military? That was crazy!"

The night Pat died, I sifted through the papers on my dresser and found his "just in case" letter. He'd written it while on an earlier deployment to Iraq and left it in our bedroom during a hiatus. When he offhandedly told me what it was, I wondered if I should open it. But the subject felt too big to talk about. So it remained there, without another comment from either of us.

The letter was both precious and awful - the last communication I'd ever have with my husband. I sat holding it for a long time, then finally started reading Pat's familiar scrawl, hearing his voice as I read: "It's difficult to summarize my love for you, my hopes for your future, and pretend to be dead all at the same time.... I'm not ready, willing or able." Then these words: "Through the years, I've asked a great deal of you, therefore it should surprise you little that I have another favour to ask. I ask that you live."

The tears I'd so far withheld on that terrible day finally flowed so fast, I couldn't breathe. Like a child, I crawled into the corner, waiting for the sobs to subside, but they kept coming. "I ask that you live." His words burned in my head as I read them again, thinking that I didn't want to live without him. He was the strong one, not me. He knew my instinct would be to give up, that sometimes I needed a not-so-gentle push. He'd seen strength in me when I didn't see it myself, and as I sat huddled on the floor, I gave him this last request. I promised to live. I knew it would be the most difficult thing I would ever do.

In some ways, I had no choice. Pat's death set off a media storm. Complete strangers mourned the loss of something symbolic, and interview requests clogged our phone lines. Meanwhile, I felt disconnected from everyone - except my sister, Christine - isolated on an island of grief. Yet I acted fine, in an effort to break free from the stifling embraces and well-meaning advice. I went through the motions of my life. I'd wake up in the house I shared with Pat's brother Kevin, the day stretching ahead of me, put on my running shoes and explore the damp streets around my house, the grief hanging around me like a thick blanket, insulating me from the world.

One day, after roaming for hours, I came home and fell onto the bed. There were a few how-to-grieve books on the nightstand that people had sent to me. After reading one particularly unhelpful bit, I threw the book across the room. As I got up, my eye fell on another volume, wedged between the bed and the wall. It was Pat's copy of Ralph Waldo Emerson's collected writings; Pat had taken it with him to Iraq. As I eagerly scanned it, an underlined passage leaped out at me: "Be not the slave to your own past." For the first time, I felt a glimmer of faith, not in something mystical but in myself. I couldn't control what had happened, but I could control my reaction. I saw two roads ahead: one of self-pity, the other less certain but lighter and more open. When a friend called not long after that to see if I wanted to join her on a last-minute trip to Hawaii, I thought of the sand between my toes and booked my ticket.

The comfort I'd found in Emerson's words led me to read other great thinkers for insight, and, a year after Pat died, I sensed it was time for some big decisions. I had always wanted to live in New York City, and I decided to move there. It was different from anywhere I'd ever known, and I could heal in my own way - no inquisitive eyes wondering, How's Marie today? I wasn't after the Carrie Bradshaw experience. I needed an energy transfusion in the extreme privacy of an anonymous place. In New York, the news of Pat's death was already ancient history. I could try on a different persona. Back home, my childhood friends were all married, and I stood out as a tragic figure. In New York, women wouldn't necessarily be married at 22, or even 42. I found a job at ESPN, and my workdays were filled with traveling and putting out fires. There was never time to think. It was ideal.

Yet I still didn't know who I was. Not only had I lost Pat, I'd also lost my identity as his wife. Even getting dressed to go out brought up all kinds of tough identity issues. I was 29, not 59, but I felt like my pre-widow wardrobe standby of skinny jeans and a slinky top suddenly wasn't appropriate. I didn't want to wear anything too revealing; dating was out of the question.

I was also worried that, as a widow, I'd be something of a broken girl in the social scene. But the more I talked with my single girlfriends, the more I realized that nearly everyone is a little damaged, one way or another. I had once had, and lost, a great love - maybe that was less damaging than having suffered a long string of less meaningful relationships. I knew how to give love and receive it - I kept this affirmation in my mind. I would not allow myself to be buried with my husband. Again and again, I'd unfold Pat's letter and let him tell me to please live.

And then, unexpectedly, I met someone through work, and his attention grew harder to cast aside. I didn't think I was remotely ready, but it did feel good to have a few butterflies. Texting led to group dinners, and one night, we kissed. I couldn't help comparing him with Pat, but I found myself leaning into the comfort of his body. I had missed this closeness, and even with this relative stranger, my body reacted. Yet from our initial meeting, I kept my life compartmentalized. We never spoke about Pat; I wanted things to stay light and fun. I wasn't ready to let someone into the deep, dark recesses of my life.

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