Black Widow’s David Harbour Wants a Red Guardian Easter Egg in Stranger Things 4

After playing a Russian prison inmate in Black Widow and Season 4 of Stranger Things, David Harbour hopes to nod at the “wild coincidence” with an Easter egg linking Alexei Shostakov and Jim Hopper. Harbour’s Marvel role as a bearded and long-haired Soviet super-soldier changed his Hopper look in Stranger Things 4, where Harbour’s American police chief sports a shaved head as the prisoner of a Russian gulag. As filming winds down on the fourth season of the Netflix series, Harbour says there’s still time for Stranger Things to pay tribute to Marvel’s fan-favorite Red Guardian.

“I’ve still got a little more filming. Maybe I can talk to [Stranger Things creator] the Duffer Brothers about that. We should put an Easter egg,” Harbour told Fandango All Access. “It’s a really wild coincidence that I wound up in two Russian prisons. I had the beard and long hair, and I was prepared to play the next season, and then this [Black Widow] came up and I was like, ‘Oh, I’m definitely using the beard and the whole thing, it’s gonna be great.’”

But when it came time for Harbour to jump from the Marvel Cinematic Universe to the Stranger Things ‘verse for Season 4, “I was like, ‘We can’t have it be the same look, guys. It’s a Russian prison,’” Harbour said. “So we came up with a whole backstory for that on the fly. They’re very good at that. The Duffer Brothers are very into using what they have, and their ideas get even better as a result of that.”

After debuting his over-the-hill hero opposite Scarlett Johansson and Florence Pugh in Black Widow, Harbour returned to Stranger Things for a “rebirth” of Jim Hopper. Believed dead by Joyce Byers (Winona Ryder) and his adoptive daughter Eleven (Millie Bobby Brown) after his sacrifice in the Stranger Things 3 finale, Hopper will “re-emerge as a different human being” in Season 4.

“There’s some fun stuff that we’re doing this season, but it’s also the heaviest dramatic stuff I’ve ever had to do,” Harbour recently told Entertainment Tonight. “We get to see a lot of Hopper at his most vulnerable, we’re gonna reveal a lot of backstory points that we’ve only hinted at in boxes in his attic. We’re gonna see a lot of these different threads, and also, we get to see a rebirth of him.”

Viewers will witness “this brutality that he needs to survive Russia” when the new season brings out “this whole other side” of Hopper — and reveals a secret five years in the making.

“There’s one thing in it that plays very big in this season that I’ve known since the first frame of the first season. Me and the Duffers would sit around and speculate, ‘Oh, wouldn’t this be cool?’ the minute we started shooting,” Harbour told ET. “We never thought we’d even get a second season, and then we get to do it in this season. It’s so satisfying to have had an idea five years prior, and to go like, ‘Oh, this is a season when we’re gonna let out this secret that we were using just as a subtle thing to inform something.’ We’re gonna lay it out finally, and it’s really cool.”

Stranger Things 4 is dated TBA on Netflix. Marvel’s Black Widow is now playing in theaters and on Disney+ Premier Access.