Last November, on the Saturday after Thanksgiving, the second- or third-best player on the third- or fourth-best team in the sixth- or seventh-best conference in women’s college volleyball took the court in Las Vegas. She was the center of attention — not only for the 300 people in the stands but for countless others as well.

Blaire Fleming, a senior, was a starter for the San Jose State University Spartans. For most of her college career, she had been a good but unremarkable, and unremarked-upon, player. Fleming was one of the roughly 6,000 players talented enough to compete in N.C.A.A. Division I women’s volleyball, but she was largely indistinguishable within that cohort. She didn’t play for a powerhouse school like Penn State or Nebraska; she had never received all-conference, much less All-America, honors. In the assessment of Lee Feinswog, a veteran volleyball journalist who writes the 900 Square Feet newsletter, she was “a middle-of-the-pack player.”

Then, suddenly, she was much more than that. A few months before Fleming’s senior season, Reduxx, a “pro-woman, pro-child-safeguarding” online magazine, published an article claiming that Fleming was “a feminine male” — in other words, that she was a transgender woman. Reduxx reported that it had found old Facebook photographs of Fleming in which she appears to be a boy, as well as an old Facebook comment by Fleming’s grandmother in which she referred to Fleming as her “grandson.” The article also quoted the anonymous mother of an opposing player who watched Fleming compete against her daughter and tipped off the publication that she suspected Fleming was transgender: “He jumped higher and hit harder than any woman on the court.”

Fleming declined to speak with the media throughout the season. But earlier this year, over the course of a series of written exchanges and a Zoom interview, she talked for the first time with a journalist, confirming to me that she is in fact transgender. Coaches and administrators at San Jose State already knew this. So did officials at the N.C.A.A., whose rules during Fleming’s time as a student athlete permitted trans women to compete in most women’s sports, including volleyball, provided they underwent hormone therapy and submitted test results that showed their testosterone remained below a certain level. Many of Fleming’s teammates, and even some of her opponents, were also aware that she was trans. “I wouldn’t really refer to it as an open secret,” one former San Jose State volleyball player, who requested anonymity to discuss team dynamics, told me. “It was just more like an unspoken known.”

But after Reduxx outed her, what was once unspoken became loudly debated — and Fleming, in her fourth and final season, went from being a mostly unknown college volleyball player to an unwilling combatant in the culture war. Five teams boycotted their games against San Jose State, choosing instead to forfeit. As the players on one of those teams, the University of Nevada, Reno, explained in a statement, “We refuse to participate in any match that advances injustice against female athletes.”