Fans of the Netflix series have been busy analysing details about the "Stranger Things" Season 4 Episode 1 title especially since it pertains to a group of villains. The premiere is called "Chapter One: The Hellfire Club," a name that may be familiar to "X-Men" fans.

Writers kicked off the anniversary of the introduction of the Upside Down in the show with a reveal of the Season 4 premiere title. They announced it on Twitter on Wednesday, which is an important day in "Stranger Things" history. It is the anniversary of Will Byer's disappearance in the Upside Down on Nov. 6, 1983.

looking for new members... are you in?

— Stranger Writers (@strangerwriters) November 7, 2019

There can only be two references to the "Hellfire Club." It is the name given to exclusive clubs attended by the rich and famous of Britain and Ireland in the 18th century. The members were often politicians who were rumoured to have taken part in immoral acts. This does not sound particularly relevant to "Stranger Things" but another nod to the title is found in the "X-Men" comics from the mid-1980s.

Specifically, "Hellfire Club" refers to the group of villains who were responsible for the Dark Phoenix saga. The club, led by the evil Emma Frost a.k.a. The White Queen, tried to control Jean Gray and convinced her to turn to her dark side.

Interestingly, there have been speculations that Eleven (Millie Bobby Brown) turns evil in "Stranger Things" Season 4. Jim Hopper's death is said to be the catalyst for her transition into the Big Bad in the installment. Given the Episode 1 reference to the "X-Men" storyline, Eleven may very well be Jean Gray, according to Digital Spy.

This is not the only time "Stranger Things" name-dropped the "X-Men." It also referenced this group of mutants in its very first episode. Fans may remember the time when Dustin raced Will on their bikes on the condition that Will will furnish him a copy of "Uncanny X-Men 134," which is the start of the Dark Phoenix saga.

Coincidental or not, the writers really know how to keep fans guessing and hyped up for the release of "Stranger Things" Season 4. Netflix has yet to announce the release date for the installment.

Stranger Things
Noah Schnapp, Gaten Matarazzo, Millie Bobby Brown, Sadie Sink, Caleb McLaughlin, and Finn Wolfhard attend the premiere of Netflix's 'Stranger Things' Season 2 Getty