Christina Hendricks knew she had to be in "Toy Story 4," even if her role in the highly-anticipated Disney and Pixar sequel was largely a mystery to her.

"They called me and asked me if I would like to do it, and I said, 'Yes' before I'd read anything," says Hendricks. "Because I thought, 'Of course.' (I'm) a huge fan of the films and know the significance of these films in people's lives. I feel like there's never been a time where I didn't know what 'Toy Story' was."

Hendricks, a six-time Emmy nominee for her work on "Mad Men," has joined the "Toy Story" ensemble as Gabby Gabby, a talking pull-string doll from the 1950s who crosses paths with classic toy cowboy Woody (voiced by Tom Hanks) in an antique shop.

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Hendricks says she only realized how integral Gabby Gabby was to the latest installment of this beloved franchise during her "magical" first viewing of the finished film.

"I never had the full script and I was working in kind of a bubble. I didn't get to work with the other actors," she says. "So I would go in a room and work with this director.

"And I was like, 'I wonder if I'm going to get cut from this film,' or 'Am I actually in it?' Like, I didn't really know how great it was, which was probably good for me because I didn't get to be as nervous as I could or would have been."

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It's been nearly 25 years since 1995's landmark original "Toy Story" introduced the world to Hanks' Woody, Tim Allen's action figure Buzz Lightyear and the rest of their playful gang.

The series' latest installment, directed by Josh Cooley, retained the heartfelt and wildly inventive core of the films but also represents a step forward in terms of representation.

"Toy Story 3" (2010) saw the series' ensemble passed down from one owner, Andy, to new kid Bonnie, and subsequently the series has become more female-focused than ever, thanks to characters like Gabby Gabby and Annie Potts' Bo Peep, returning to the series for the first time in 20 years.

"I think it's important for them if they're going to make another one, you have to evolve," says Hendricks. "You want it to be true to what it is and the heart that has always been there, but if you don't change with the times, then it seems like it would be a mistake."

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Since last being seen in 1999's "Toy Story 2," Bo Peep has, like the films and society at large, changed a great deal over the last couple of decades.

"Bo Peep is like a warrior," says Hendricks. "She's the leader of everybody and it's just such a strong, great, role model character. It's so wonderful to watch her do it."

Gabby Gabby, because of a manufacturing defect in her voice box, is at the heart of one the most resonant themes of "Toy Story 4": What happens when people get hung up on what they perceive to be their imperfections?

"There are so many movies where there are bad guys and good guys," says Hendricks, and Gabby Gabby starts out as what audiences will think of as a bad guy. "And we realize that everyone has a story, and there's a reason why we become who we are, and you have to hear that story to understand them."