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Things don't get any easier for Eleven in Stranger Things' upcoming fourth season.

Speaking to Entertainment Weekly, star Millie Bobby Brown — who plays Eleven — opened up about the darker turn her leading character takes in the show's long-awaited return. "You get to see Eleven in the darkest state she's ever been," she said.

"This has definitely been the hardest season I've ever filmed," the 18-year-old English actress continued. "And there have been some of the scariest, scariest things that I've ever seen as a human, which you guys will get to see, for sure."

As a refresher, the show's third season concluded with Eleven losing her powers. She will now need to reflect on her past in order to potentially get them back — and that means having to revisit her experience of growing up at the shady Hawkins National Laboratory.

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"That storyline of her as a young child wasn't covered. There were still so many questions, from me and from the viewers," she told the publication, adding that fans will "get to see that this season."

After its third season premiered in 2019, Stranger Things — which first arrived on Netflix in 2016 — went on a long hiatus due to the COVID-19 pandemic. Its much-anticipated fourth season is being split into two parts, with the first arriving on May 27 and the remaining episodes debuting on July 1.

Brown recently revealed that season 4 "leads back to The Upside Down."

Courtesy of Netflix

"Eleven is obviously [having a] high character arc and this season is incredible," she told Collider. "You guys definitely get to see things that you have been questioning, you get answers, which is super great. It was also really nice for me to be filming that and to understand more of Eleven's background, but you guys will get to deep dive into that for sure [in] Season 4."

Additionally, Brown's costar Noah Schnapp previously told PEOPLE the new season is "unexpected, romantic and exhilarating."

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"I think this season is going to be the best one yet," added Schnaap, 17. "It's something to be excited about."

In February, series creators Matt and Ross Duffer announced their plans to end the acclaimed sci-fi drama after five seasons. A timeline for filming and its release has yet to be confirmed.

The first half of Stranger Things' fourth season premieres May 27 on Netflix.