Kristen Bell Reveals What She Was Really Drinking in Her Wine Glass in 'Woman in the House' (Exclusive)

ET spoke to Bell about her new Netflix series and some BTS secrets, including what was really in that filled-to-the-brim wine glass.

Kristen Bell is letting us in on a few secrets about her new Netflix series, The Woman in the House Across the Street From the Girl in the Window.

ET's Lauren Zima spoke to Bell and her co-stars, Michael Ealy and Tom Riley, about the dark comedy and what was really in those filled-to-the-brim wine glasses the 41-year-old actress drank out of on the show.

"The first day it was grape juice, and I had a sugar crash, and we figured out that hibiscus tea was a better option," Bell revealed. "It's really tart and it's delicious. I was so hydrated during this show. There's never been anyone 80 percent water, and I'd say I was 99 percent water during this whole show. So, a lot of runs to the bathroom, but I quite enjoyed the hibiscus tea."

Bell plays Anna, a woman watching the world pass her by from her living room window, with a full glass of wine in hand. What starts out as a mundane part of her routine quickly turns dangerous when she becomes witness to a gruesome murder.

While the wine starred as a character of its own, there was another object that stole the show, the all-knowing casserole.

"The casserole had its own dressing room, and we weren't allowed in," Bell joked. "I guess it was like food safety and stuff. I never had an inanimate object as a scene partner, and I guess I enjoyed it, but by the end I can do without the smell."

"I think Kristen, at this point, you need to go back to Netflix and add the casserole to the title. I think it should be the Women in the House With the Casserole Across the Street From the...," Ealy quipped of the show's hilariously long title.

The cast not only had to make room for some of the show's inanimate objects, but for some of the "good bad acting" they had to adjust to in the mystery spoof series that's a take on all those woman-gone-mad-in-the-house films.

"That's the joy for us, for me especially, that's the main joy of it, was letting go of that bit of you that feels you're not able to crank the dial to be able to get this scene quite right." Riley shared. "It felt like when you were feeling like that, incredible writers and directors would say, 'No that's good,' just lean into the fact that it feels bad."

For Bell, it was about letting the genre be in charge.

"It was a strange thing for me of realizing as an actor, you want to be in charge because you want it to be real, you want it to feel very real, like a real human being is interacting and saying these lines. And in this show, you had to let the genre be in charge," Bell explained. "So, like, in any of my scenes with either of these boys, I couldn't feel real. I just needed the genre to feel real and if the genre was in charge, then we were nailing it."

With all the twists and turns the satirical psychological drama takes, the cast chose to keep the show's biggest surprises a secret from their families so they could enjoy the murder mystery along with the rest of Netflix's viewers.

"I didn't let him see any of this," Bell said of letting her husband, Dax Shepard, get an early peak at the show. "He didn't read any of it because I want him to be able to watch it and have all the surprises as an audience member."

"Same deal," Riley agreed. "It was very much a case of, 'I'm not gonna show you because the end you don't want spoiled. Trust me."

Ealy kept it from his wife too, who kept questioning the Fatale actor about the project.

"My wife kept asking me, 'What is this about?' because I was so secretive about it, and I was just like, 'I promise you, you'll love it. Just please leave me alone so we can watch it when everybody else does. I cannot talk to you,'" Ealy said. "I started making up the fact that I had to sign NDAs and stuff like that just to get her to stop asking."

Watch along with the cast and their families when The Woman in the House Across the Street From the Girl in the Window premieres Jan. 28 on Netflix.