‘Gone Girl’ Author Gillian Flynn on Thriller’s Screenplay: ‘It Was in Good Hands’ (Video)

Gone Girl author Gillian Flynn is still reeling over the success of her best-selling husband-and-wife thriller, two years after it hit bookstores' shelves.

STORY: 'Gone Girl': 8 Big Clues From the First Trailer

"It was really wild because, first of all, the book did better than anyone thought, so it became this kind of cool thing," Flynn told Good Morning America of the title that's sold over six million copies and is now available in paperback. "And I was like, 'Oh, well, that's great. That's enough,' " but then I had a screenplay to complete. "It's so exciting. It's this really wonderful thing when it goes out in the world and kind of takes on its own life."

When asked about rumors that the book's controversial ending may differ for its big-screen adaptation, she responded, "I cannot give away, in good conscience, the ending of the movie, but I wrote the screenplay, so it was in good hands.

STORY: 5 Things to Know About the First 'Gone Girl' Footage

"People, I think, were kind of worried that it would turn into, you know, a musical or something, or the feel-good hit of the summer, and it's not that!" she joked.

Watch the interview below:

Email: Ashley.Lee@THR.com
Twitter: @cashleelee

Ashley Lee