A premiere date for season 4 of the Netflix show has not yet been announced

Stranger Things Season 4 Is Reportedly Filming at a Prison in Lithuania: Is Hopper Alive?

Warning: Stranger Things season 3 spoilers ahead!

Could Jim Hopper return in the fourth season of Stranger Things?

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Though Hopper was (spoiler alert!) seemingly killed off at the end of season 3, the post-credits scene of the finale revealed that an unnamed American was being held captive by Russians. Many fans wondered if Hopper — whose body was never shown — could be the mysterious person being held in the Russian prison cell.

According to a new report from Murphy’s Multiverse, season 4 of the hit Netflix show is set to start filming either later this month or in early in February — but instead of filming in its regular location of Atlanta, the show will reportedly begin production in Lithuania.

Murphy’s Multiverse reports that the filming in Lithuania will take place primarily on a prison set, as well as in and around locations used in the HBO miniseries Chernobyl.

After wrapping up in Lithuania, the show will reportedly return to Atlanta to complete filming.

A representative for Netflix did not immediately respond to PEOPLE’s request for comment.

Image zoom David Harbour in Stranger Things Netflix

If Hopper (David Harbour) is indeed the American in the Russian prison cell seen at the end of the third season, the Netflix show filming in Lithuania could mean that fans haven’t seen the last of him.

“Well, here’s the thing. I always knew that Hopper had to make a sacrifice,” Harbour said about his character’s apparent death. “Like, he’s a jerk, and he also needs to pay for that in some way … so I thought he’d make the sacrifice.”

Harbour explained that when he saw the post-credits scene, he also assumed that his character survived.

“And I was like, ‘Oh, clearly I’m the American,’” the actor said. “And then I haven’t gotten many phone calls.”

To prove his point that even he was left in the dark about the ending, Harbour FaceTimed series creators and producers Matt and Ross Duffer, known professionally as the Duffer Brothers, in an attempt to get some answers.

“Am I dead? Is Hopper dead?” he asked them.

“I mean, we’re still figuring it out, David,” Ross replied cheekily.

“You guys are a ton of help. Really wonderful work. Good luck with season 4,” Harbour told them.

After his character’s apparent death, Harbour, 44, spoke to PEOPLE at the Stranger Things junket about whether or not fans should expect to see him moving forward.

“I’m very happy doing the show and I think there’s a rich tapestry to draw on from all the characters,” Harbour said in July. “I wish the best for the show no matter what. And in terms of my involvement, I love the show, but we’ll have to see what happens moving forward. I don’t really know. The Duffers, I do believe, have a plan, but we’ll have to see what they have in mind.”