(Photo via DianaGabaldon.com)

Diana Gabaldon at a book signing.

After two decades and 25 million book sales, Arizona author Diana Gabaldon is a literary sensation. Now, one of her book series called "Outlander" has been made into a hit TV series.

"Sing me a song of a lass that is gone, say, could that lass be I. Merry of souls she sailed over to see and skye. Billow and breeze, islands and seas. Mountains of rain and sun. All that was good.”

Fans recognize this is the theme song to the "Outlander" television series.

The first Outlander episode aired in the U.S. last month, captivating about 5 million viewers across multiple media platforms. The series is based on Diana Gabaldon’s eight-book saga. It follows a married World War II combat English nurse transported into mid-18th century Scotland. The novels stretches the genres of fantasy, adventure, romance and history.

“I think they’ve done absolutely fabulously with all of it," Gabaldon said.

It’s not unusual for show creators to adapt a story from the page to the screen, but Gabaldon said executive producer Ronald Moore respected the heart of the work. Starting with lead character Claire Randall, the strong and sassy heroine who’s torn between her love for the 20th century husband she left behind and a new-found love with Scottish warrior Jamie Fraser. 

“When he showed me his pilot script for this series, I said, 'You know, this is the first thing I’ve ever read based on my work that doesn’t make me either turn white or burst into flame,'" Gabaldon said.

Gabaldon said she wrote "Outlander" in the late 1980s as a sort of “practice novel.” Just writing bits and pieces of a book to get her started into writing something other than what she studied as a PhD student of Ecology at NAU. She studied animal behaviors.

“My doctoral dissertation was entitled 'Nest Site Selection in the Pynion Jay Gymnorhynus cyanocephalus,'" Gabaldon said. "Or as my husband says, 'Why birds build nests where they do and who cares anyway.'"

Gabaldon wrote the books’ settings and characters based on what popped into her head.

Some of the male characters came easily. Claire, on the other hand, was a different story.                                                                                      

“The third day of writing, I introduced this English woman," Gabaldon said. "No idea who she was, what she was doing there and what she would be doing next, but I loosed her into a cottage full of Scotsmen to see what she’d do.”

That’s when Claire starts realizing she may be an Outlander and begins her quest to return to her own time. She’s ultimately forced to marry Jamie to save her life and a passionate love affair flourishes. And although millions tune in to watch it every Saturday, there is no greater fan than Gabaldon herself.

“I wrote the book, I know what happened, and at the same time I watch the daily footage and I’m wondering, boy I wonder what happens next, 'cause I don’t know," she said.

The show creators do take some liberties adding some of their own story lines. And as a show consultant, Gabaldon gets peeks into what will air. She admits the characters are all an extension of herself and the love story inspired by her own family.

Gabaldon reflects on her deceased parents, her father a native of New Mexico of Spanish descent and her mother from Flagstaff of English background. With glistening eyes she said it was a marriage that almost didn’t happen because of prejudices in the 1940s. And her mother longed for her true love.

“They sent her to Tucson to school there so she would forget him theoretically and all that," Gabaldon said. "It lasted for about six months. In December she called my dad and she said 'I still love you.' He drove down and got her that night and they were married the next morning. Yeah, I’ve seen, you know, that kind of marriage that close.”