'Big Little Lies' Author Liane Moriarty on the Power of Reese Witherspoon and That Twist Ending (Exclusive)

Getty Images

Because of the time difference between L.A. and Australia, when Liane Moriarty hopped on the phone with ET this week, she was technically already one day closer to Sunday's premiere of Big Little Lies, the HBO limited series adapted from her best-selling novel. "It is getting nearer and nearer!" the author exclaims, then adds reassuringly, "I feel very confident everybody's going to love it."

It helps if you consider the talent behind the series: Big Little Lies stars Reese Witherspoon, Nicole Kidman and Shailene Woodley as Californian mothers whose seemingly perfect lives begin to unravel following an incident at first grade orientation, culminating with a murder. All seven episodes were written by 10-time Emmy winner David E. Kelley (Ally McBeal) and directed by Oscar nominee Jean-Marc Vallé (Wild). Moriarty discusses that powerhouse team, the changes made to her source material and why her husband hopes Jennifer Aniston stars in her next movie.

ET: I'm shocked that this is your first book that will reach the screen, just because of how popular each has been. Why do you think Big Little Lies is the first?

I think it's the first because of the incredible efficiency of [executive producer] Bruna Papandrea and Reese Witherspoon and Nicole Kidman and Per Saari. It's their two production companies working together. It's Bruna who said to me, "Well, this is the way that it should happen." But my first novel, Three Wishes, was optioned years and years ago and What Alice Forgot is still in the works and The Husband's Secret is still in the works, so I've just experienced what so many other authors have -- that it takes a long time. Other authors always said to me, "Don't get too excited until the day they start shooting." But Big Little Lies just beat them all!

Do you remember your first kernel of an idea that became Big Little Lies?

There were a few little kernels, but the first one was definitely that I was on a book tour with another author whose name is Ber Carroll. She's a lovely Irish author. We were in New South Wales in Australia and everywhere we went she was looking for the perfect necklace to wear to a school trivia night, because she and some of the other mothers were planning to dress up as Audrey Hepburn. Afterward I just got fascinated. I wanted to see how she and all the other mothers looked, so she sent me a photo and then I was thinking, "Imagine if all the men had dressed up as Elvis..."

That was one kernel, and then the other was a story that somebody told me about when her daughter started at school and she and another little girl came out of the classroom with bite marks on their arms. So, of course, all the mothers were in a flap saying, "Who bit you?" And the little girl was saying, "A boy did it." Because it was the first day of school, they couldn't name who the culprit was so they got all the little boys to line up, like a police lineup. When I heard this story, I was just enjoying this tiny little suburban drama and imaging how the mothers would feel thinking, "Please don't let my little boy be identified as the biter on the first day of kindergarten." In this case, the little girls finally gave in and admitted that they had bitten themselves, just to see what marks it made on their arms. [Laughs] But I kept imagining what would have happened if they'd picked a boy at random and said, "He did it."

When you wrote it, did you ever have a dream cast in mind? Or picture actresses in any of these roles?

No! I never cast my books from the beginning. I always joke about the fact that once I started getting some of this Hollywood interest, when I sat down to write my most recent book, I did for a moment think, "I should write a book with a role for Meryl Streep in it." [Laughs] But I think it's a mistake -- it immediately freezes you up. It's the wrong way to write. In fact, with Truly Madly Guilty, my most recent book, I couldn't imagine that as a film at all, but it's been optioned by the same team as Big Little Lies. So, it goes to show. I think it stifles my creativity if I start thinking of it as a film.

What do you think makes Reese right for the role of Madeline?

I guess it's just her bubbly nature and that she can play the comedy side of it so perfectly. I mean, when I heard that she was wanting to play Madeline, I immediately thought that she could do it beautiful. I don't know! I don't know what it is, but she does it! It's her talent. I don't know how any of them do it. As somebody with no acting ability, I think they're all amazing.

Do you remember what your initial thoughts were when you found out that Nicole and Shailene had been cast as Celeste and Jane?

I was thrilled with all of them! People will be embarrassed with me, but I didn't recognize Shailene's name. Then, when I looked her up, I knew her from her first movie with George Clooney. The Descendants, I think it was. And she's gorgeous! As soon as I saw her face, I thought, "She's perfect, absolutely perfect, for my Jane."

I love that Nicole would have still worked in the cast, had they kept the book set in Australia.

Oh, yes, exactly! That's right! Originally they were thinking that, of filming it in Australia. I think that was the original thought. But it's a universal story, so it works everywhere.

Do you think that changing the setting had any affect on the end product? Do you think there is a big difference between Australian moms and American moms?

No, I don't think there is. The only tiny thing I do think was the school trivia night -- and I was on set when they were filming it and everybody looks gorgeous and all the costumes are perfect. The only thing that would have been different in Australia is that there would have been lots of men making a really sort of hopeless attempt at being Elvis with a really crummy outfit. I think that's the only tiny difference. Everybody wouldn't have gone for it quite as much as they did with the outfits.

What was it like on that first day visiting set, when you saw these huge movie stars playing your characters and this world that you created coming to life?

It was so surreal. And I was so lucky that I got to be there on the night that they were filming the school trivia night. I think that was special too, because I think all of the crew had been working so hard towards that night. Which is similar to when I was writing the book. Because I always knew the trivia night was going to be my big scene, I couldn't wait to write it.

When I saw Nicole all dressed exactly as I've described her in the book, I felt unexpectedly emotional to see her. She just looked so beautiful. And I loved Reese's outfit, too. I have to admit that they changed her outfit from what I had in the book, but it was better, actually! It fit with my character of Madeline and what she would have worn that night.

Was there a scene or quote or bit of dialogue from the book that you thought absolutely needed to stay in the show?

The only thing I said to Nicole when I first met her was with some of the domestic violence scenes, it was important that she hit back. That was an important part of the book to me, that she felt complicit in their violence. It was nice to see some little sentences exactly as they were from the book. I enjoyed hearing Reese deliver the line that she "tends to her grudges like little pets." I said to David E. Kelley, though, there were some parts where I'd be watching the filming or watching the end product and thinking to myself, "I hope I wrote that line and not David." But there were parts where it'd be a line of mine and then a line of his or he'd tweak it a little bit and make it better. So, it was interesting.

What do you think was the biggest change made from the book to this series? Was there one change onscreen that you were particularly like, "Oh! What an interesting choice!"

Yeah, they took Madeline's storyline in a different direction. And I do understand why they needed to do that, for the series. I guess my Madeline in my book wouldn't have done that, but you know, that's fine! That was probably the only [thing]. And the show, the musical, that's her interesting new storyline that they added in. In a way, I actually really enjoyed the parts that were not in my book, because I found it easier to suspend belief, I think, in those parts. Because I wasn't involved in it, so I could just watch and enjoy those parts.

Having watched the entire series and having this go from being an idea in your head to the book to now an HBO show, when you finished that last episode what was your reaction to the whole thing?

Well-- [Laughs] I will admit that when I first watched, I somehow thought they had finished it 10 minutes earlier than they had. And then I saw Bruna and Nicole and I was saying, "Is that the ending?" And they were saying, "Yeah, yeah," and I was thinking to myself secretly, "They're all mad!" There was a while when I had to admit I was thinking all the reviews are going to say, "That ending is ridiculous." Then I finally worked out that I hadn't seen the whole thing! So, when I saw the true ending, my feeling was of great relief that it was a wonderful ending, compared to what it would have been if it had finished 10 minutes earlier.

So all the fans, make sure you stay for the last 10 minutes!

Stay for the whole thing! I don't know what happened. I think it was technology to blame in some way. Imagine it ending 10 minutes earlier than it does and you'll see what I went through, thinking, "They're all crazy in Hollywood!"

Do you know if there was ever consideration at any point of doing something big, like changing the twist of the book for the show?

No, no. That was right from the beginning, all of our discussions. That worried me, that they might do that. I think I would have been upset if they'd changed the twist, because I know my readers did love that side of it. But no, right from the beginning there was no discussion of changing it.

You mentioned some of your other books that are in the pipeline of being brought to the screen. Jennifer Aniston was attached to What Alice Forgot a few years back--

I think she still is. I think that's still a possibility. And my husband deeply hopes that it is still a possibility. When I told him that Jennifer was attached to that, oh, I've never seen such a light in his eyes. He was so pleased with me. [Laughs]

The Husband's Secret was -- or is, hopefully -- also in development. Have you heard any updates on that one?

Yes, they have been sending updates on that one and apparently there is still a good possibility, as well. I think the script might have been finished, so I'm still hopeful that both of them will still finally come to screen.

With Reese and Nicole now signed on to produce Truly Madly Guilty and having come out the other end on Big Little Lies, do you have any specific hopes for what that will become? Now that these big names have gravitated towards your work, have you had any casting suggestions you've given them?

No, and part of my problem is I never know anybody's name. [Laughs] They're all sort of laughing at me because I'm saying, "You know, the guy, we've seen him..." The only thing with Truly Madly Guilty is it's about a small incident, so it couldn't possibly be a series. I wouldn't have wanted it to be, because it's about something that happens at a backyard barbecue. So, it would definitely be a movie. That's the only thing that I said to them and they agreed.

As for yourself, are you working on a new book at the moment?

I am! I am in the very, very early stages, yes. And I'm deliberately not casting roles for now. [Laughs] I'm in the exciting stages -- well, the exciting and terrifying stages -- where I'm not sure where it's going to go.

Can you give us a small tease for what we can expect?

No, I don't think I can! Because, honestly, I could completely discard [everything]. All I can say is that I used to make this joke about how my next book was going to be set on a tropical island and I would need to do lots of research to make it accurate. That was a joke, but the more I've made that joke, that may actually inspire [the book]. So, something about a vacation -- that's what it may be about. But it may not be! It may be something totally different!


EXCLUSIVE: Reese Witherspoon Talks Parenting at 'Big Little Lies' Premiere With Lookalike Daughter Ava

EXCLUSIVE: Laura Dern Jokes That Her Upcoming 50th Birthday Isn't Really a Milestone: 'We Don't Discuss Age'

Nicole Kidman and Reese Witherspoon Cover 'Elle' with 'Big Little Lies' Co-Stars!