In some distant, imagined future she does historic things. Running with a long, brown ponytail floating behind her like a vapor trail, she wins gold medals, breaks world records and restores track and field to a place where little girls dream that someday they will be just like Mary Cain. Or in another version of that same future, she is injured or overwhelmed and never finds the greatness that once seemed imminent. It's not possible to know which will happen, despite America's collective obsession with thrusting outsized expectation onto the most gifted young athletes. Whatever her path, whether to greatness or obscurity, there will never be another moment in her life quite like this one, when every race is fast and every day is sweeter than the one before.
She is less than two months past her 17th birthday, a year shy of high school graduation and now indisputably the most precocious female middle-distance runner in U.S. history. Last Saturday afternoon in blistering sunshine and angry winds at Drake Stadium in Des Moines, Cain broke open the 1,500-meter run at the USA Track and Field national championships with a brave, and very grown-up, burst of speed just under a lap from the finish, then held on for second place to claim a spot on the U.S. team for the world championships in Moscow in August. She is the youngest U.S. athlete to make a worlds team since the event began in 1983.
Cain's performance, in which she was caught in the final strides by training partner Treniere Moser, 31, was the latest in a six-month string of transcendent races. In 2013 she has broken indoor and outdoor high school and/or junior records in six events at distances from 800 through 5,000 meters. She became the first U.S. high school girl to break two minutes (1:59.51) for 800 and ran 4:04.62 for 1,500, a time that, in combination with her sensational finishing speed, puts her on the cusp of challenging the best runners in the world. She will have that opportunity in the coming weeks as she trains in Europe with members of the Nike Oregon Project, whose coach, Alberto Salazar—who coaches her as well—expects Cain to race a 1,500 in London on July 26 and possibly run at an earlier meet in Monaco before heading to the worlds.
She is caught for now in a giddy limbo, with one foot stretching into a very adult athletic and media world that stands poised to heave a huge slab of the sport's future across her slender shoulders, and one foot hanging back in Bronxville (N.Y.) High, where her friends—"We're the nerds of the grade," she says. "I am a complete nerd, I am not cool at all"—will chide her for taking only two AP classes next year instead of a possible five. (She insists that a globe-trotting track and field career "should count for at least four APs.") After busting up her elders in the 1,500 field in Iowa, the 5'6", 113-pound Cain came rushing into the media interview area clutching a tiny yellow stuffed duckie named Puddles. Following a recent training session in Park City, Utah, she blessed herself in the team van, prompting Salazar to ask if they had passed a roadside memorial that he had missed. "No," said Cain, both a Catholic and an animal lover, "there was a dead deer back there."
On Sunday morning she sat in a quiet hotel lounge in downtown Des Moines, still excited about selecting her USA gear at formal team processing the previous night. She is both suddenly famous in a small way and suddenly quite stunned by that fame. "It's so weird that people tweet about me," she says. "And my Facebook is overwhelming. I don't want to hurt anybody's feelings by not accepting their friend requests, so I don't accept anybody, then I get the big in-box." She doesn't have her own Twitter account, but there's a fake Mary Cain account. ("I'm pretty interesting on there," says Cain, mock seriously.) Her phone is a low-tech, text-and-calls-only Verizon Razzle. Cain says, "I'm a dinosaur." But a smart one: She avoids track-website message boards, which can be vicious and are demographically disconnected from her world. "All those old men [critiquing her]," she says.
She likes to read Hemingway and Fitzgerald, but also Mitch Albom's The Five People You Meet in Heaven. She watches Modern Family and How I Met Your Mother. In the midst of a thoughtful answer to a serious interview question, she spoke the phrase "until after Moscow" and then shot her arms into the air and yelled, "And I am going to Moscow!" She followed that by channeling the movie A Good Day to Die Hard (which she knows only from having seen the trailer in hotel rooms): "Welcome to Moscow!" And then laughed at the silliness of her own joke.
Cain is the daughter of Charlie, 50, an anesthesiologist, and Mary, 48, a homemaker, both New York City natives. They have four daughters, Aine, 19; Mary; Catherine, 13; and Máiréad, 11. Neither Charlie nor Mary was an exceptional athlete, but the younger Mary was a strong youth swimmer and soccer player. The first hint of her running talent came when she did 5:47 for a mile at a fifth-grade field day. In seventh grade she qualified for the 3,000 meters at the New York state championship meet and a year later ran 2:11 on a 4 × 800-meter relay. As a freshman she won the Class C state cross-country title, and by the middle of her sophomore year her training had been transferred to Bronxville High boys' coach Ed Stickles, who had run college track under distance-training guru Jack Daniels at Cortland (N.Y.) State. "It was a very easy job," says Stickles. "Great big engine, fast wheels." At the Olympic trials in Eugene she finished fifth in her heat and did not advance.
When Stickles left Bronxville High after the trials, Cain was left without a coach. She trained through the summer on her own, making sure to sprint the last 200 meters at the end of workouts to preserve her kick. "We were in a tough place," says Cain. "We actually discussed, as a family, whether I should just wait two years until college to run again."
Salazar, who is best known to one generation as the fearless marathon champion of the 1980s and to another for coaching, among others, Mo Farah of Great Britain to the gold medal in the 2012 Olympic 10,000 meters and Galen Rupp of the U.S. to the silver, noticed Cain's times and pulled up YouTube videos. He saw her win the Penn Relays high school mile in 4:39.28 and finish sixth in 4:11.01 in the 1,500 at the world junior championships in Barcelona last July, despite running hunched over, with her left arm flailing across her chest. "I thought, Wow, this girl is running fast doing a lot of things wrong that are easily fixable," says Salazar. He called the Cains, even as they had considered calling him. Mary, the mother, sprinted to answer the call as Salazar left a message.
"We really needed divine intervention," says Charlie. "Our daughter has a wonderful gift, and we wanted to help her. We were struggling."