'Stranger Things' breakout star Priah Ferguson on Season 3 and her 'cool stunts'

Amid a stacked cast of talented young actors, becoming a breakout star on a hit series is no easy feat. And yet, that's exactly what Priah Ferguson managed to do in Season 3 of the Netflix drama "Stranger Things," as spunky Erica Sinclair.

At just 12 years old, Ferguson brings a heaping scoop of sass with her re-introduction as Lucas's (Caleb McLaughlin) little sister, who goes from demanding free ice cream samples at Scoops Ahoy to helping save the day in Hawkins, Indiana.

Ferguson's Erica sees more screen time this season as part of the so-called Scoops Troop – Dustin (Gaten Matarazzo), Steve (Joe Keery) and newbie Robin (Maya Hawke) – to investigate the shady underground Russian dealings at the Starcourt Mall.

Onscreen and off, Ferguson's tiny frame is filled with a big personality.

"Erica is definitely confident. She's a leader," Ferguson says. "She says what people think. She did a lot of cool stunts."

One of the best: Shimmying her way through the mall's ventilation system like an undercover agent.

"I've always had a love for action and stunts, so that was kind of my first little stunt that I've done," Ferguson says. "At first I was scared; I wasn't just brave to go into the vent. I was like: 'Am I really going into a vent? What if I get stuck?' "

Since the season was released July 4, Ferguson has been promoting applesauce and yogurt-pouch seller GoGo squeeZ's "BE Time," encouraging kids to get outside for more unstructured fun (and maybe a little undercover work).

Under the surface of Erica's attitude, viewers find out she's got layers. She's actually kind of a math nerd, calculating complex equations in her head in a matter of seconds.

"I'm definitely a nerd," Ferguson says. "Math isn't one of my favorite subjects, but I'm pretty good at it. I'm a history nerd; I love history so much. I think everybody has a little nerdiness to them or a little quirkiness in something they're really passionate for."

The third go-round leans heavily into the 1980s and the beginning of suburban youth mall culture, where Erica thrives.

"I got more into the '80s, and now I'm an '80s fan because I listen to the music and I'll watch movies like 'E.T.' and '80s shows like 'He-Man,' " says the markedly Gen Z star, who cites the musical stylings of Roger and Zapp Band as her favorite of that era.

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Ferguson also opens up about her castmates.

"Maya, Joe and Gaten were really welcoming when I came into the cast, and (when) I worked with them, they were just super sweet," she says. "I learned a lot of advice from the whole cast, like how to always stay kind."

But it wasn't all work: "We shot movies behind the scenes; we would sing 'Hamilton' in the makeup trailer. Me and Millie (Bobby Brown) actually shared a school trailer."

Ferguson says Matarazzo was the funniest on set, and while the entire cast became her "big brothers and sisters," she's not in their group text chat because "they're talking about driving cars, and I'm over here talking about riding my 10-speed."

"I'm really excited about Season 3 right now," Ferguson says. And who can blame her? She hasn't fully had the chance to celebrate her moment.

"But if there's a Season 4, I think it's going to be awesome."

As one of Netflix's most popular series, she (and fans) won't have to worry.

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This article originally appeared on USA TODAY: 'Stranger Things' star Priah Ferguson talks Season 3 breakout role