PROLOGUE I''m alone, out front. I''ve just dropped the only woman between me and the 2018 Boston Marathon finish line. I brace for her to respond, to reappear in my peripheral vision. I hold my breath-- ot an advisable tactic at Mile 22--and I count. One . two . three . four .

five . Nothing. Still by myself. I exhale, releasing months of tension. Young Kenyan runner Gladys Chesir has been aggressive for most of this race. If I can''t hear her footfalls on my heels by now, that means she''s vulnerable. It''s time to ratchet up the pace and inflict pain. I''ve visualized this scene, taking the lead coming off Heartbreak Hill, thousands of times over the last decade.

I''ve pictured myself strong, confident, and pulling away under a brilliant blue April sky to win one of the most pres­tigious marathons in the world. This moment looks nothing like that. Rain is sluicing down in sheets, relentless. A fierce head­wind batters my face, my chest, my quads. My hands are numb, and my feet are beyond sodden. There''s only a scat­tering of people watching by the side of the road, and if they''re cheering, the sound is muted by my drenched head­band. And yet. This is where I''ve always wanted to be.

It''s a rare juncture in any career, and there''s no guarantee it''ll ever happen again. I have to yank myself out of my old sun-splashed dreamscape and be fully present here, now. I need to adapt to the opportunity that has opened up in front of me, on this course I know by heart. It''s been a scant few hours since I stood barefoot in my darkened hotel room, completely devoid of hope, feeling none of the tenacity that had always defined me. I had ar­rived in Boston without my usual game plan to maximize my chances for a win. My typical meticulous checklist was down to one item: survive. That all shifted after the start gun, with absolutely no planning on my part. Improvisation has brought me this far.

Now it''s time to channel the instincts and knowledge I''ve sharpened and stowed away over twenty years. I''ve run thousands of miles so I would know what to do in the next four. I press the Play button in my head and hear the voice of Frank Browne, my high school coach in California, whose combination of drive and irreverence once pulled the best out of me. "I know you have the ability. One day you''re going to be in position and say, ''Fuck it,'' and pull the trigger on one of these races." I let out another deep, explosive exhale. My mind clears of everything but one thought: Can I win this thing? THE OUTSIDER It was my fault I was finishing up my last mile in the dark. My dad had pestered me all day about getting the run in, and out of spite, I''d procrastinated.

The sun was setting by the time he drove me to the Silver Strand, a scenic sandbar that connects the towns of Imperial Beach and Coronado, just south of San Diego. People were packing up and leaving the beach, wiped out from hours of soaking in the sun and playing in the waves, as I started out on the flat north- south road. He followed me on his bike to keep me company. I was running at a good clip about five miles into an eight-mile run when I realized I hadn''t heard the sound of my dad''s wheel for at least ten minutes. I knew one of his tires was losing air, and he''d been working hard to keep up with me. I could have stopped and waited for him to fix it; instead, I decided to press harder, to make him hurt, to make him worry about me being out there by myself. I leaned into the pace a little bit more, visualizing how I''d close out a race at the high school state meet. My dad was the chasing pack, and I was laying on the gas, putting them away for good.

I was so deep in my race dream by the time I hit the parking lot where we''d begun that I almost missed it in the pitch-black. Once I slowed down and walked a few strides to catch my breath, I felt a deep sense of accomplishment about putting in the miles. I was glad I hadn''t talked myself out of it. My dad had said that would happen the whole time he was pushing me to get out the door, but I would never tell him he was right. I sat on the curb next to his truck in satis­fied silence. Fifteen minutes later, I began to hear the telltale squeak and the faint thud of a flat tire. By then, I already had a long, complicated competitive history with my dad, Dennis. Growing up, my older sister, Natalie, and I were required to play sports year- round so that we''d be too busy to get in trouble, insulated from a world our parents viewed as full of bad influences and dan­gerous pitfalls.

We didn''t have the luxury of taking a season off, for fear that we''d become lazy, and we were expected to be willing to try it all. Dad scoured the newspaper for new activities, then woke us up first thing on Saturday morning to tell us what he''d signed us up for: golf lessons one week, coed Tball the next. From the time I joined my first organized soccer team at age six, he held his own clinics for us after he got off his job as a construction worker-- post-practice practices, as we thought of them. We did soccer drills, kicking a size 3 ball against the low retaining wall that bordered our front yard in San Diego while he barked instructions, or juggling the ball with our feet to master the ideal first touch. He coached our softball team, and when Natalie decided she wanted to pitch, I was happy to be her personal catcher. These were not casual sessions; they were about self-improvement, not en­joyment. He''d snap if we weren''t being serious enough in his eyes, like the time he ripped into Natalie for smiling too much as she tried to throw strikes. We were close in every way, born just eighteen months apart, and she was perfect in my mind--beautiful, adventurous, better at sports than I was.

I couldn''t understand why he would criti­cize her for something that had nothing to do with how well she was pitching. I hunkered down, hiding behind my catcher''s mask, thinking, What level of fun are we allowed to have? He wouldn''t let it go and kept antagonizing her all evening. I had learned not to argue. We kept working hard to appease him and meet his demands to be aggressive on the field, to earn more playing time, to avoid embar­rassing him. Our mom, Nancy, had a more passive, level personality but was just as committed to our sporting life. She built her entire schedule around us, punching in for her shift as an AT& T operator at five in the morning so that she''d be off in time to pick us up from school, shuttle us to practices and games, and watch and critique every moment of play. In the ultimate parental sacrifice, she often agreed to stand in as goalie--without the benefit of gloves. She defended the goal as if her life were on the line, and left the field exhausted and bruised from shots that had ricocheted off every part of her body.

If we weren''t playing sports, we were watching them. My parents were die-hard San Diego Padres fans, and when the ball games stretched past bedtime, Natalie and I would wake up to find sticky notes with the final score posted on our bed frames. I inherited that baseball DNA and idolized out­fielder Tony Gwynn, the perennial All-Star who''d starred at San Diego State University and never never left the city. He was as much a part of my hometown as the beaches and the US Navy base. As I got older, youth soccer became as much of a frustra­tion as a passion. I was an instinctive forward, quick to the ball, but too slight to put enough punch into my shots and often overpowered oneonone. If I didn''t hold my own when things got physical, I''d be on the ground and soon on my way to warm the bench. " You have to play bigger than you are," coaches told me.

"Believe you''re bigger . " It was my first taste of being labeled an underdog--tiny finesse player battling it out among flying elbows and kicks to the shins, the one who didn''t belong but was determined to make it work. That was hard enough, but what really both­ered me was the political crap. You didn''t have the newest shoes? See ya. Didn''t live in the upscale La Jolla neighbor­hood? Take your ball to a different group. Mom wasn''t will­ing to sleep with the coach? So long, starting lineup. The culture struck me as nuts. I understood that competition was supposed to teach us how to succeed.

I developed an early taste for success, but I resented my dad''s compulsive, vicarious need for me to achieve, as if I couldn''t be trusted to want it badly enough for myself. When the ball sailed into open space, I was ex­pected to meet it perfectly every time, to avoid wasting the smallest opportunity. He hammered home his messages: " No shortcuts." "Nothing is given, everything is earned." "Do it twice, but the effort only counts once." All solid con­cepts, but the sense that he was in this with me was offset by continual reminders that I owed him for anything I accom­plished. The better I did, the more indebted he made me feel. When he shelled out extra cash for a private lesson to shore up a weakness, he let me know how much it cost and how easily he could take it all away.

The only person who could fully appreciate what it felt like to walk that tightrope was my sister. Natalie and I were constantly managing how to reconcile our dad''s good in­tentions, his desire for our lives to be better than his, with the way he came across. We navigated it differently. She was more willing to push back and battle it out verbally, while I tended to simmer and pick my spots. We each respected how the other on.