SPOILER ALERT: Do not read if you have not yet watched the season premiere of “American Horror Story: 1984” entitled “Camp Redwood.”

Welcome back to “American Horror Story,” which in its ninth season travels back in time to the 1970s and 1980s to play in the slasher genre.

Only one episode into the season, it already looks to be a fun ride because “1984” is the first season since “Freak Show” to be set in the past. (Yes, “Hotel” had some other eras popping up, but it was mostly set in the present day.) This year seems like a real treat for campy horror, though, harkening back to not only the original “Friday the 13th” movies but also the fun knockoffs like “Sleepaway Camp” and “Summer Camp Nightmare.”

This is also the first season without Sarah Paulson or Evan Peters. Losing not one but two heavy-hitters leaves “Horror Story” with some big shoes to fill; luckily, Leslie Grossman and Billie Lourd have come on strong in recent years to fill that Paulson void. And this season is positioning Emma Roberts back into small-screen scream queen status for the first time since, well, “Scream Queens.”

“American Horror Story: 1984” actually began a decade and a half before its titular time period — in 1970 — with some counselors at Camp Redwood having a threesome in a cabin while the campers slept. But before things got too risque for basic cable, one of the girls got freaked out by hearing some “jingling.” Someone had come for the young adults, stabbing her bedmates first and then getting her, too. The trio was left in a bloody pile — but not before Mr. Jingles (John Carroll Lynch) sliced their ears clean off to keep as his trophies.

The weird and very “Horror Story” thing about these murders was that it wasn’t just the horny counselors who were killed; Mr. Jingles then slaughtered the entire cabin full of campers. While early speculation may have led viewers to assume he was killing those he deemed sinners (especially because of how much the head of the camp talks about sin and Jesus in the episode), this revelation seemed to prove that untrue. His deeper motive — if he has one — remains to be seen.

After some ’80s-tastic opening credits — seriously, those might be the best “AHS” credits of any season — it was now 1984 and we met all our main characters in an aerobics class taught by Xavier (Cody Fern), which was an amazing sequence of ’80s hair, spandex and pelvic thrusts.

They quickly blow out of town because summer in 1984 Los Angeles, Calif. is a hot and uncomfortable place. The Olympics rolling into town, which not only ruined traffic but also upset Chet (Gus Kenworthy) because he was kicked off of Team USA at the last minute for testing positive for drugs. But furthermore, the city was being terrorized by the Night Stalker, a real-life serial killer portrayed on the show by Zach Villa. In reality, the criminal born Richard Ramirez killed 14 people in 1984 and 1985 before being caught; on the show, he broke into new LA transplant Brooke’s (Roberts) apartment looking for jewelry before being scared off by neighbors threatening to call the cops. The attack was all the motivation Brooke needed to join her new aerobics buddies and get out of Dodge.

In reality, just in case you’re curious, Ramirez did the majority of his killings in 1985 and wasn’t called “the Night Stalker” until then. But that’s not super important to the “Horror Story” story. What “Horror Story” seems to be attempting to do is explain what Ramirez was up to during his conspicuous absence from June 1984 to March 1985. And it turns out, that is stalk “the one that got away” Brooke at Camp Redwood. But more on that later.

On the way to camp, the kids met a grizzled old gas station owner who advised them to stay away from Camp Redwood — “They never shoulda opened that place up again … you’re all gonna die.” — which is a great cliche. But soon enough they have a brush with death as they hit a man on the road. The man had injuries he sustained before being hit by the van, but no one seemed too concerned about how he obtained them. Xavier completely freaked because he was driving, telling the other kids to get their stories straight that they didn’t hit this obviously lost and confused hiker. But, rather than leave him on the side of the road like other horror movies have done, they brought him to the infirmary at camp. 

Finally arrived, the kids get a tour from the new owner, Margaret (Grossman), who revealed herself to be a “godly” woman who bought the camp to provide a good Christian safe haven for kids for the summer. But then Rita the nurse (Angelica Ross) spilled the beans about Benjamin Richter, nicknamed Mr. Jingles because of his jingling keys, a Vietnam vet who went on a murderous rampage one night in 1970 … and Margaret revealed she was the only survivor. She was the star witness in Mr. Jingles’ trial. So, the counselors were suddenly wondering just what the hell they got themselves into.

As this big reveal was happening, the poor hiker woke up and discovered one of his ears had been cut off. So, if Mr. Jingles was convicted and sent away, as Margaret said, who cut off this new guy’s ear?

There wasn’t time to dwell on that, though, because Matthew Morrison showed up sporting a tank top, a pair of short-shorts, an outstanding porn ‘stache … and apparently a giant penis. No, seriously, there was a whole plot point about how he was originally supposed to be front row next to Jane Fonda in her workout video but “one part of him” kept pulling focus. It certainly sounded like a line, but Montana (Lourd) said she had seen the original video before it was reshot and it was the first thing to which she ever masturbated. Montana and Trevor (Morrison) ended up skinny-dipping in the lake, but before things could get fully intimate, a storm started to roll in and the far-away lights freaked Montana out enough that they went back inside.

It wasn’t just the storm that was proving dangerous for the new inhabitants of the camp, though, as a nearby institution experienced a break-out — by one Mr. Jingles, no less. After faking his own suicide in his cell, he killed an orderly and just casually strolled out — but not before pressing the button to open all of the cell doors, allowing his fellow mentally unstable inmates to wander freely, too. Most of them appeared to be staying close to their home, so to speak, but Mr. Jingles slipped away into the night.

Back at camp, there was a flimsy excuse to send Brooke off on her own, where she came across hiker’s body hanging on the back of a door (or did she?) and then ran through the woods to escape Mr. Jingles. Again, or did she? This chase sequence was intercut with the Olympic torch ceremony, which was a little weird. And then of course, when Brooke tried to show everyone the hiker’s body, it was gone, so now nobody believed her about what happened. Plus, Margaret showed up minutes later in a raincoat similar to what Brooke said she saw Mr. Jingles wearing and everyone assumed she just got a contact high and could not be trusted.

But of course, this is “Horror Story” so murderous characters really do lurk around every corner. In the waning moments, Brooke answered the ringing payphone at the camp and heard nothing but jingling, while Richard Ramirez watched her from the woods.

So far, this season of “Horror Story” feels like it is set up to have a great “And Then There Were None” or “Harper’s Island” vibe to it — the elements of “who is going to die and when” is a really fun part of the mysteriousness of the story.

“American Horror Story: 1984” airs Wednesdays at 10 p.m. on FX.