“Who?” I ask, even though I know exactly who she’s talking about. I saw her leaving gym class just as we arrived. She was red-faced and sweaty. There’s no way she’s as good a runner as I am.

“You know, that weird new girl?” Gaby laughs. I just shrug. The less I talk about her, the better.

“Remember,” Mr. Martin announces to the class, “you’re just trying to improve from your last time.”

“That won’t be hard for me,” says Gaby, giggling. She never takes anything seriously. Schoolwork, sports, nothing. She just goes with the flow—which, in the case of the mile run, isn’t very fast. Sometimes that’s what I love about her (especially when she’s going along with whatever I say), but sometimes it drives me crazy. “I don’t even remember my last score,” she says.

I know exactly how fast I need to go if I want to beat my last time of six minutes, fifty-two seconds. During the mile run last year, I beat the fastest boy, Joaquin, because his shoe came untied and he tripped. My plan is to beat him again.

“This isn’t a competition,” Mr. Martin says. He readjusts his hat and then brings his whistle to his lips.

I crouch down and tighten my shoelaces. Even if it’s not a competition, when you’re known as the fastest runner, you have to beat your time—and everyone else’s.

“Runners, take your marks!”

My body tenses, ready to go. The rush of blood pounds in my ears. From somewhere, like in a dream, I hear the teacher shout, “GO!”

I catapult forward. I pump my arms, move my legs. I forget about Gaby and Joaquin. My mind loosens, concentrates only on the path in front of me. I keep Mr. Martin’s orange cones to my right as I race along the outside of the field, run toward the parking lot. I love the feeling of the turn as my body leans and balances.

“Mercedes!” I hear Gaby shout, but I ignore her.

“Think you’re fast just ’cause you’re named after a car?” someone just inches away from me says. From the corner of my eye, I can see that it’s Joaquin, trying to beat me this time. He thinks he’s so funny. But I won’t let anyone distract me.

Not even Mattie Gómez. Not only do our faces look alike, we’re also about the same height with the same long legs. I wonder if she is as fast as me, if she also likes the feeling of letting go as you run like a wild horse.

To my left, someone is passing me. It’s Dante now. My pace has slowed. This is all Mattie’s fault! Why did she have to appear in my city? At my school? In my grade? At least we don’t have phys ed together.