A 25-year-old Texan just landed a six-figure book deal for her wildly popular fan-fic starring Harry Styles and the boy band. What's next?

If One Direction fan Anna Todd wrote her own lyrics to the group's hit "Story of My Life," it would sound like a fairytale. The 25-year-old Texan just scored a six-figure advance when Simon & Schuster imprint Gallery Books acquired the rights to "After," her steamy fan-fic story about Harry Styles and the boy band that has been a hit on the digital self-publishing site Wattpad for over a year. (United Talent Agency is shopping the film rights as well.)

Fan fic, in which amateurs write and share unauthorized adventures featuring established characters or real people, has been big business for many years. "Fifty Shades of Grey" started as "Twilight" fan fic. But this is the first big deal to involve a "Directioner," as members of the massive 1D fan-fic community call themselves. (Other big musical subjects of RPF - real people fiction - include Beyonce and 5 Seconds of Summer).

"After" imagines a bad-boy punk version of Styles falling for sheltered college freshman Tessa, whose world is upended by their relationship. Todd put the story up in daily installments - some 300 short chapters spread out across three volumes - on the relatively new Wattpad, where it was an almost instant hit. Wattpad's Ashleigh Gardner says that even before Todd finished the first volume, "After" was registering all over the company's internal social media metrics, with fan-generated art and custom musical playlists popping up on Twitter and Instagram. When Todd mentioned "Pride and Prejudice" or "Wuthering Heights" in "After," Wattpad had spikes in the reads (how the company counts clicks) on those novels on its site.

To date, "After" has notched more than 800 million reads and ended 2013 as the site's most-shared story. Wattpad reached out to Todd, helped her build her fan base during the next two volumes and guided her toward a book deal, essentially acting as her agent.

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Beginning in November, Gallery Books will publish a reworked version of "After" that will turn Styles into a fully fictionalized character in the way that "Twilight" characters Bella and Edward were reworked into Anastasia and Christian when "Fifty Shades of Grey" went from fan fic to traditional book. If Todd is even a tiny bit as successful as E.L. James, who has sold more than 70 million copies of "Fifty Shades of Grey," she'll be writing new verses of that fairytale song long into the future.