Audience members might have been a bit confused by the X-Men: Apocalypse post-credits scene, which introduces the Essex Corp. The scene takes us back to the Alkali Lake facility, where Stryker had taken Mystique and others, and Jean, Scott, and Nightcrawler stumbled upon Weapon X, aka Wolverine. The brief scene showed a group of men walking past the dead bodies to the lab and collecting Wolverine's blood, X-rays, and other information, putting it all in briefcases labeled "Essex Corp." This new corporation might sound obscure, but Essex Corp is so important to the X-Men, and the reference sets up multiple future films.
Fans of the X-Men comics can tell you that Essex Corp is an allusion to Nathaniel Essex, the villainous Mr. Sinister. In the comics, Sinister has a history of experimenting on mutants, so it's no surprise that he would be after Wolverine's DNA. In fact, though previous X-Men films and Apocalypse directly link Stryker to the experiments which transformed Wolverine's skeleton and made him into Weapon X, it's possible that Essex Corp was also involved. (Essex Corp's retrieval of Wolverine's blood could also be a reference to the fact that Nathaniel Essex revived the Weapon X program to experiment on mutants in the comics.)
Most believe that the appearance of Essex Corp, and the implied involvement of Mr. Sinister, is setting up the next X-Men movie, tentatively called Wolverine 3. Recent casting news reported by Variety revealed that actor Boyd Holbrook will play a villain who is "the chief of security for a global corporation pursuing Jackman's Wolverine character." It's also possible, however, that Holbrook is playing a different character entirely. The character description appears to suggest that Holbrook will play a human, while Mr. Sinister is a mutant, with powers extending from super strength and slowed aging to telekinesis and shapeshifting. Furthermore, given that Essex Corp seems to be named after Nathaniel Essex, wouldn't Mr Sinister himself be the CEO, not a "chief of security"?
In an interview with Collider, Apocalypse writer and producer Simon Kinberg revealed that the post-credits scene featuring Essex Corp was indeed meant to directly relate to future films, though not to Wolverine explicitly. "Certainly the Wolverine movie is related to what happens at the end of it, but there's also another character that's introduced, at least in name, in the tag and he could show up in any host of different X-Men films," Kinberg said. In addition to connections with Wolverine and the X-Men, Kinberg also said that Nathaniel Essex (the character who is introduced "in name") could play a part in the Gambit movie, which Fox has had in the works for a while now, with Channing Tatum attached to the role.
Essex Corp could also potential be connected to the next Deadpool movie, which would allow Fox to bridge the gap between Deadpool and X-Men: Apocalypse . There are many different theories as to how exactly Essex Corp and Mr. Sinister could be involved with Deadpool. One is that Essex Corp could potentially be the driving force behind the experiments conducted on Wade Wilson. In the comics, Deadpool is part of the same Weapon X program as Wolverine, and though the new X-Men timeline has complicated things, it's possible that Deadpool could be a victim of modern-day Weapon X testing. Another possible connection involves Cable, the time-traveling mutant who is rumored to appear in the Deadpool sequel. In the comics, Mr. Sinister is directly involved in Cable's creation (it's a long story involving Jean Grey, Scott Summers, and some seriously messed up trickery). So if Cable is in Deadpool 2 , it makes sense that Mr. Sinister might also make an appearance.
Theories and future movies aside, whatever Essex Corp is doing in the X-Men universe, it isn't good.
Images: 20th Century Fox; Giphy (2)