Spoiler alert: A major plot point is revealed at the end of “Stranger Things” Season 3 — do not read further if you want to be surprised.

Still here? Season 3 of Netflix’s hit ’80s nostalgia show takes a leaf out of the “Game of Thrones” book and seemingly axes one of its main characters in a shocking plot twist.

But is police chief Jim Hopper (David Harbour) really dead? Signs point to no. Hopper’s “death” happens in the season finale, when he’s stuck in a room with the inter-dimensional machine the Russian scientists have been conducting sinister experiments on. He was attempting to disable it with Joyce Byers (Winona Ryder), but their plan goes awry, leaving him in the non-ideal position right next to it. He signals for her to press the button and disable it, even though that means he vanishes into the mysterious void.

It’s an act of willing sacrifice by him — to save everyone.

David Harbour as Jim Hopper and Winona Ryder as Joyce Byers in “Stranger Things”Netflix

Season 3 ends with his distraught adopted daughter Eleven (Millie Bobby Brown) moving in with the Byers family, as they get out of Hawkins (not a bad idea, honestly). Everyone thinks Hopper is dead — there’s even a newspaper headline that reads, “Hero chief dies in fire.”

But wait. Don’t turn it off yet when the end credits roll. There’s a scene halfway through them, set in Kamchatka, Russia.

We cut to a secret lab facility with prisoners behind doors. Russian officers take one unlucky soul and feed him to the Demogorgon, the monster from the show’s first two seasons, who’s apparently still at large. But the most important part of that scene comes before they single out the doomed prisoner: First, they pause at the closed door next to his, where there’s another unseen prisoner.

“No, not the American,” one Russian says.

This is almost certainly Hopper. Of course, we don’t see who the “American” is behind the closed door of his prison cell, so it could be someone else. But he’s really the only candidate, and he’s likely not shown for maximum suspense when it’s revealed he’s still alive next season.

Somehow, in his vague “death” in the mysterious machine, he got transported to a prison in Russia. Or maybe his friends just assumed he was dead, but the Russians found him in the lab after everyone left. Either way, the story of how he ended up there will be revealed next season — and it’ll be up to Eleven and her pals to rescue him.

Netflix has not yet officially confirmed a Season 4, but producer Shawn Levy has.

“Stranger Things” Season 3 is now streaming on Netflix.