November 6 is a very important day in Hawkins, Indiana — it's the day Will Byers initially went missing on Stranger Things in Season 1. And since 2018, the Stranger Things social media accounts have taken the opportunity every year to commemorate the special occasion as "Stranger Things Day" by unveiling special videos from the set, blooper reels, and announcements for upcoming seasons.

Last year, the series' writers' room revealed on their Twitter account the title of the premiere episode of Season 4, putting out feelers for new members to join "The Hellfire Club."

And as of June 18 this past summer, all the scripts are in for Season 4. Sans titles, much to fans' chagrin.

As the Stranger Things social media accounts are ever adept at meme culture, they hopped on the "How it started" vs. "How it ended" train for this year's Stranger Things Day, instead changing "How it ended" to "How it's going," as filming is currently in progress on shooting Season 4. Gaten Matarazzo, who plays Dustin Henderson, further confirmed that they're "in the middle of filming" during a Twitch livestream as recently as Halloween.

This year's post verified that a certain member of the Stranger Things cast answered their call for joining the club. None other than the aforementioned Dustin himself.

In addition to the logo art, Stranger Things offered up some first look shots of Dustin in the club's raglan sleeve shirt. The newest recruit can also be seen waving the club's flag.

As per usual, the Stranger Things accounts never want to divulge too much, horsing around of "me knowing nothing about HFC yet running for Club President."

Well, what do we know about the so-called HFC? Who do we think will be members aside from Dustin? Will "The Neverending Story" be the club's anthem? Let's hope not. While we're in limbo till 2021 at the earliest, I rounded up some of the most thorough Reddit theories fanning the flames of this Hellfire Club.

1. It's Most Likely A Club For The Younger Stranger Kids, With Dustin As The Ringleader

As the photo of Dustin confirms, I'd wager we're gonna see Dustin, Mike, Lucas, Max, Eleven, and Will walking into school wearing their branded club gear. We've seen in season's past how the kids like to band together, whether via Ghostbusters Halloween costumes or as they argue over a game of D&D.

@theupsid3down is on this bandwagon, sharing via Reddit that they "hope it's the name of a club the younger cast make for themselves."

With Dustin as the first official member, and considering the fact his yearbook photo is the profile picture of the @strangerwriters account on Twitter, it's also possible he could have an even bigger role next season as the ringleader of the group.

2. Here Come The Marvel & X-Men References

But where would the inspiration for the group come from? The Internet is ablaze thinking the Hellfire Club directly refers to the X-Men comics, as Will and Dustin trade X-Men editions in the pilot episode.

@dougsawerewolf deemed the Duffers really "old-school X-Men fans," as they recalled how Will and Dustin negotiate over a critical X-Men comic, #134, featuring Jean Grey in the pilot. They essentially offer up Eleven as a parallel to Jean Grey becoming Dark Phoenix.

"X-Men #134 is a critical part of the 'Dark Phoenix' saga, involving Jean Grey. Jean Grey is Phoenix, a member of the X-Men with incredibly powerful psychic powers - influencing others and moving objects with her mind, etc. In the issues leading up to #134, Jean Grey, is abducted [sic] and brainwashed by The Hellfire Club, a powerful secret society dressed as colonial LARPers who want to exploit her powers. When she's finally rescued, she suffers a psychic break, essentially giving into her alter-ego, Dark Phoenix. Dark Phoenix ends up destroying a bunch of stuff, ends up an intergalactic villain [sic], and ultimately destroys herself to save her friends and humanity."

@sexypolarbear22 thinks that the other X-Men cosplay roles will be filled out with Max as Storm, Dustin as Wolverine, Luke as Colossus, Mike as Cyclops, Will as Nightcrawler. "And I guess Steve could be Charles [Xavier]." That may not be too far off, as Steve is the pretty damn good babysitter of the group anyway, advising these burgeoning adolescents on their merry ways, possibly in between future shifts with Robin at the video store.

3. Are Kali & Her Group Of Superhuman Cohorts Their Own Hellfire Club?

But taking the Marvel theory even further is u/greatal398, who thinks that because Eleven is still struggling with her powers by the end of Season 3, she will reach out to her sister Kali, whose new group of power players are deemed "the Hellfire Club" by El's friends in Hawkins.

Marvel fans y'all know what's up. El's still unable to use her powers at the end of ST3, so it would make sense for her to visit her sister, who had helped her with developing her powers before. I believe that Kali has left that original group from Season 2 and has been looking for or meeting up with other test subjects to fill the void that El left. It'd be cool if this new group of superhumans were called the Hellfire Group by the original Party, who I hope still get decent screentime, even with the season set away from Hawkins supposedly. El won't get her powers until their storylines converge, and only then will anyone be able to rescue Hopper from the Upside Down.

4. If Kali Unleashes Eleven's Inner "Dark Phoenix" Will Mike Help Reel Her In As Stranger Things' Scott Summers?

Turning to Kali though may bring about the "Dark Phoenix" possibly latent inside Eleven. @mileventurkey does a deep, intricate dive into the X-Men #134 - #136 comics as akin to the rise of Dark El, which they shared in a series of pictures of Instagram.

Re-shared for the convenience of Reddit users, the theory suggests that these three comics display the key points of Stranger Things Season 4. "In the opening moments of the very first episode, Will references X-Men 134, the beginning of "The Dark Phoenix Saga" (a famous Marvel storyline that follows the corruption of a telekinesis mutant named Jean Grey) and 'The Hellfire Club' is a secret, villain mutant group in the these comic books." In the Stranger Things world, they think this translates to Kali creating a group like this with three of the new characters TVLine teased would join the cast in Season 4. "They want revenge on the society and government or their goal is to find and destroy Brenner, who they know is still alive."

But on the other hand, the theory contends that El seeks weak visions about Hopper and deeply believes that he is still alive. But since her powers are not back, she goes to Kali and her secret cohort. @mileventurkey relates Kali to Jason Wyngarde/Mastermind from the comics, as they share the same powers, and he slowly manipulated Jean Grey into doing his bidding on behalf of the Hellfire Club, but she eventually broke free of his control.

"As you can see, Jean fights against Mindmaster and says 'You came to me when I was vulnerable. You filled the emotional void within me.You made me trust you...and all the while you were using me!' I can see the same scenes for El and Kali. El needs to bring back her powers to find [her] father, and Kali will somehow manipulate her (like Mindmaster) while helping her."

Lastly, just like Jean, the theory posits that El will see the error of Kali's vengeful ways and will want to leave the Hellfire Club, while Mike and her friends come to help her, casting Mike in the Scott Summers/Cyclops role. "Scott aka Cyclops is Jean Grey's boyfriend. Throughout the entire Dark Phoenix Saga, Scott tried to help his true love. He fought for her and brought her to the good side with his love."

5. New Teenage Characters Start The Hellfire Club & Try To Pull Eleven Away

But as the initial Stranger Things Day post sharing the first episode's episode title asked for new members, one Reddit user thinks the club was founded by three of the new characters likely to join Season 4 with less of a supernatural subplot. TVLine reported that "the adolescent trio range from a metalhead to an entitled jock to a character that sounds an awful lot like the twin of Fast Times at Ridgemont High stoner Jeff Spicoli."

u/Animestrangerthings claims that the Duffers have said the original gang and the new kids on the block will be enemies and that the rumor mill churned out that one of the teenagers might be Eleven's new love interest, inspiring the theory that "the new teenage characters have a party like Dustin, Mike, Lucas, and Will. But instead of being called the Party, they are called the Hellfire Club, and they are going to ask Eleven if she wants to leave the party and join them instead."

Well as of now, it's pretty clear Dustin is a member of the Hellfire Club. Was he also lured away by these new characters?

6. A Club Jonathan Joins At NYU?

Reddit users have also been aflutter regarding Jonathan Byers' desire to attend New York University, and how the Hellfire Club can also refer to secret, exclusive societies aside from just those featured in the X-Men comics.

"The Hellfire Club was a name for several exclusive clubs for high society rakes established in Britain and Ireland in the 18th century," @theupsid3down recalled. "Obviously all speculation at this point but I wonder if it's Jonathan [sic] at NYU being inducted into a secret society or something like that??"

7. But Worst Of All, Is It Really A Club Rooted... In Hell?

Like the mythbusters the Duffer Brothers are, they never like to let their homages on Stranger Things to be one-dimensional, and the Hellfire Club looks no different. As @MouthBreather85 surmises, in a scarier twist that would make even the Mindflayer shiver, the obvious nod "to look at is the X-Men one because X-Men has been referenced before in the show. But we can also look at the real Hellfire club, and assume that [the] S4 antagonist will be far greater than even the Russians. That there's some secret shadow society/club pulling all the strings, and the US and USSR are just the puppets in the grand scheme of things."

While we still have no clear indication yet of the inner workings of this Hellfire Club, we can guess that comics will in fact come into play ultimately, and the X-Men route is a favorable track to go down.

As @Little_Consequence mentions, every season has highlighted different themes from 80s culture in the U.S. "D&D in S1. Video games in S2. Mall culture in S3. Comics in S4."

Whatever hell the Upside Down unleashes in Season 4, we'll be ready, club signups in hand.