Not many people saw X-men: Apocalypse when it was in the theaters this summer (if the box office gross is anything to go on), so you might’ve missed the end-credits teaser, which introduced Essex Corp. as a potential new antagonistic player.Considering that there aren’t any official plans yet for another X-men film featuring the main cast, it stands to reason that Essex Corp. will be playing a role in the upcoming Wolverine film, set for release in 2017, but before this weekend, it was unclear as to how.However, with the release of the X-men: Apocalypse DVD and Blu-Ray, we now have an answer. According to Cinemablend, writer/producer Simon Kinberg, and director Bryan Singer confirmed in the audio commentary that this does refer to the unofficially-titled Wolverine 3.Since many of you might’ve missed Apocalypse, the sequence takes place at the Weapon X facility, where a man takes a vial of Logan’s blood and puts it into a briefcase with an “Essex Corp.” label. It’s short and vague and is a reference that would go over the heads of non-comics fans.Essex Corp. is an entity in the Marvel universe that mainly refers to Nathaniel Essex, a man and mutant, known more commonly as Mr. Sinister. Essex was a 19th-century scientist that devoted his life to unethical experiments on mutants and the genome. After being exiled from society, he came across the mutant Apocalypse, who transformed him into the immortal and powerful Mr. Sinister.While this doesn’t outright state that Mr. Sinister will be the villain in Wolverine 3, what we already know about the film makes this theory plausible. Actor Richard E. Grant, who you might know from Bram Stoker’s Dracula or about half of BBC’s television lineup, was cast as a “mad scientist.” While Boyd Holbrook, from Netflix’s Narcos, is reportedly stepping into the role of the lead villain–identified only as the head of a security organization pursuing Wolverine–this would leave room for Grant to pick up the Sinister mantle.If any character in the X-men universe could be slapped with a “mad scientist” label, it’s definitely Mr. Sinister.Previously, Kinberg had been coy about what the teaser meant, telling Collider that it could set up for any number of X-men sequels, including New Mutants or Gambit, if either become real, in-production movies.Little is actually known about the new Wolverine sequel, which is supposed to be Hugh Jackman’s last appearance as the character. We know it’ll star Jackman and Patrick Stewart as Charles Xavier and that it’ll be drawing elements from the Old Man Logan story in the comics (not all of it, since the crux of that story, is based too heavily in Marvel lore). We also know that it’ll be rated “R.”However, according to director James Mangold, audiences should expect to see footage very soon.