Growing up, Nnedi Okorafor never envisioned a career as a writer. She had her eye on tennis. Nationally ranked at Homewood-Flossmoor High School, the daughter of Nigerian track stars dreamed of going pro. And after a year playing at the University of Illinois, that seemed a real possibility. Then one day, at 20, she woke up paralyzed from the waist down. Something—doctors never learned exactly what—had gone wrong during a routine scoliosis surgery.

Her tennis career was over, but a silver lining emerged. “I sat in that stinking hospital room documenting my fears and fantasies,” she later recalled in a blog post. Okorafor, now 43, eventually regained her mobility, but those fantasies fueled countless short stories and a pair of breakout novels. The first, 2010’s Who Fears Death, about a postapocalyptic Sudan, was recently optioned by George R.R. Martin for an HBO series. The second, Akata Witch—dubbed “the Nigerian Harry Potter”—led to a sequel, Akata Warrior, coming out this fall.

Akata Warrior, which follows a 12-year-old albino girl who discovers she’s descended from Nigerians with supernatural powers, took Okorafor six years to write—because, she says, “I needed to travel and gather and listen.” She made several trips to Africa and dug into her research at home, even stumbling upon Nigerian mythology. Her diligence shows: The writing is confident, sweeping, and steeped in magic, including an entire subplot about an ancient Igbo ideographic script.

Though the Akata series is aimed at young adults, Okorafor’s books are far from Pollyannaish. Who Fears Death, for example, tells the story of a Sudanese teenager who describes herself as “obviously a child of rape” and explores such brutal themes as genocide and female mutilation. Don’t expect Okorafor to tone things down for TV, either. “I’m excited to see how the story of one of the most complex characters television has ever seen unfolds.”