Author Amy Boesky reveals she lived a double life when she was in her twenties and ghostwriting for the popular teen book series Sweet Valley High.

For everyone else, Amy Boesky was a Harvard graduate studying 17th century British literature at Oxford. However, only a few who knew her well knew that every weekend, Boesky moved from being a student to a ghostwriter for the popular teen book series Sweet Valley High.

"It was ... a sort of [an] antidote, a kind of escape hatch from the more rigorous world of scholarship and academia in which I was living," she tells NPR.

Boesky has written more than 50 books for the series under the pseudonym of Kate William. The author reveals that until she started writing for the series, she had no idea Sweet Valley High existed. She met Francine Pascal, the creator of the series, at a friend's dinner party about a year after the books launched. Since she was interested in writing and looking to publish her own book, she decided to write for the series. For the selection process, Boesky was asked to write one chapter and a chapter outline.

"I discovered that the voices of these girls, not only Jessica and Elizabeth, but their friends, resonated with my own," she says. "And I found that enormously fun to write. The world of Sweet Valley was this ... very 1980s, Reagan-era, suburban utopia. I think maybe it did help, in some ways, for me to theorize what these idealized places are that we're so drawn to. "

For every book, Boesky would receive a plot outline from Pascal that was about eight or nine pages long. After going through it, she would come up with a subplot.

"I would be reading with bated breath to see what was happening with the characters, especially as I got more and more involved in it," she says. "With my subplots, it would always involve Jessica, who I loved. Jessica was always trying to get ahead, get in the way of other people."

She finally stopped ghostwriting after she finished her doctorate program and got her first job. When she started teaching at Georgetown University, she thought it would be too weird to continue crafting the teenage tales.