The monster is back in Season 3 of “Stranger Things” — and it’s joined by a “Mormon.”

Well, probably.

Netflix starts streaming new episodes of the popular horror series on July 4, bringing back all the characters who lived through Season 2. It’s almost a year later — the summer of 1985 — and things are about to get really scary again.

In Episode 1, Dustin (Gaten Matarazzo) returns home to Hawkins, Ind. — the site of all that supernatural mayhem in the first two seasons — from a monthlong stay at science camp. And, to the surprise of his friends, the teenager met a girl there.

“Girls go to science camp?” Mike (Finn Wolfhard) asks — a minor example of the 1980s-esque sexism that accurately pervades “Stranger Things.”

“Suzie does,” Dustin replies. “She’s a genius.”

But she’s not just smart, he assures his friends. “Think Phoebe Cates, only hotter” — another true-to-the-’80s line.

But Suzie lives in Utah, so Dustin enlists his friends to lug equipment up the highest local hill to set up a super-powered radio tower he’s built so he can contact her.

“You know, I’m pretty sure people in Utah have telephones,” Max (Sadie Sink) says.

“Yeah, but Suzie’s Mormon,” Dustin says.

“Oh, s---,” Lucas (Caleb McLaughlin) says, “She doesn’t have electricity?”

“That’s the Amish,” Max replies.

Having grown up back East, I can say without hesitation that it wasn’t unusual for people to confuse members of the LDS Church with the Amish or Mennonites. That was definitely true in the ’80s.

(By the way, it’s accurate for the characters in “Stranger Things” to use the term “Mormon” to describe members of The Church of Jesus Christ of Latter-day Saints in 1985, a third of a century before the church president announced that was offensive. They’re no doubt still using the term in Indiana today.)

“What are Mormons?” Lucas asks.

“Super-religious white people,” Dustin replies. “They have electricity and cars and stuff, but since I’m not Mormon, her parents would never approve. It’s all a bit Shakespearean.”

Yes, Dustin likens himself and Suzie to Romeo and Juliet. And his friends, unsurprisingly, wonder if Suzie actually exists.

That question ... will be answered. I’m not going to spoil it for you. And not just because that plot point is on the long list of Things Netflix Told Critics Not to Reveal.

There is a logical reason why the Demogorgon — the monster from the alternate dimension known as the Upside Down — is back to wreak more havoc in Hawkins. I’d tell you that one, because it’s revealed in the opening moments of Season 3, but that’s also on the Do Not Spoil list.

And by logical, of course, I mean it fits within the “Stranger Things” reality, where teenagers save us from that monster from an alternate dimension.

(Photo courtesy of Netflix) Finn Wolfhard, Noah Schnapp, Sadie Sink, Caleb McLaughlin and Millie Bobby Brown in Season 3 of “Stranger Things.”

At some point, it’s going to be hard for “Stranger Things” to keep this narrative going. But the Duffer brothers — creators/writers/executive producers/directors Matt and Ross — haven’t gotten there yet. Season 3 is tense and scary and surprising and gross — a crazy monster movie spread over eight episodes.

And it’s plausibly, and sometimes hilariously, true to the ’80s. A whole lot of Season 3 takes place at the new mall in Hawkins, and in 1985 the local mall was the place to be. And the placement of cans of the ill-fated New Coke is 100% on point — it was introduced in April 1985.

The characters we’ve come to love are as compelling as ever. And, in a totally no-spoilery way, if you’re invested in them, you’re going to laugh and you’re probably going to cry.

Will there be a Season 4? Netflix hasn’t officially confirmed it yet ... but you can judge for yourself whether you think it’s happening by the way Season 3 ends.

Spoiler alert: I think the answer is ... yes.