The X-Men Tease In Doctor Strange 2 Only Hardcore Fans Noticed

Contains spoilers for "Doctor Strange in the Multiverse of Madness."

It's been a long time coming (at least, in this universe), but "Doctor Strange in the Multiverse of Madness" is finally here. The bold new chapter of the Marvel Cinematic Universe pushes the Master of the Mystic Arts further than ever before, as he's thrown into different realities in his fight to save America Chavez (Xochitl Gomez) from being killed by a supernatural entity. Like many big blockbusters of the last few years, it was met with production delays due to the pandemic, but the sequel finally gives fans the live-action multiversal adventure they've been looking for thanks to Chavez's powers.

Stephen Strange (Benedict Cumberbatch) is a little wiser this time around, although he's mourning the life he could've had with Christine Palmer (Rachel McAdams), who gets married just as the adventure begins. The idea that there are alternate worlds where he winds up being with Christine is a tantalizing idea for the sorcerer, and it's a sentiment Scarlet Witch (Elizabeth Olsen) shares in this turn as the surprising main villain.

Wanda Maximoff is looking for a universe where she can be with her sons, Billy (Julian Hilliard) and Tommy (Jett Klyne) after the events of "WandaVision." But the adventure across the multiverse sees Doctor Strange meet a mysterious council of heroes who have sworn to protect their universe and beyond: the Illuminati. Fans already got a glimpse of the team in the trailers, recognizing Patrick Stewart's voice and iconic yellow chair. We can now gladly confirm: He reprises his role as Professor X.

But there's another surprising "X-Men" tease in the scene –and this one only hardcore fans noticed.

It was only a matter of time before we started to get major "X-Men" characters in the MCU after Disney bought Fox back in 2019. As most fans will already know, the "X-Men" and "Fantastic Four" franchises exist in their own separate universes — although "Deadpool" makes plenty of jokes about Marvel Comics and the MCU with his signature fourth wall-breaking humor. Although many expected Marvel to simply reboot the X-Men to fit the MCU, the studio is clearly taking a slightly different approach, since Patrick Stewart returns from the original movies to play Charles Xavier again — although this time he's in the yellow hover chair.

When the film first introduces the council, we see that it's made up of Mr. Fantastic (John Krasinski), Black Bolt (Anson Mount), Karl Mordo (Chiwetel Ejiofor), Captain Carter (Hayley Atwell), and Captain Marvel (Lashana Lynch). It's an incredibly surprising scene, and Professor X's late arrival only adds to the spectacle — especially because the theme song from the original "X-Men" animated series heralds his debut. Oh yes, they really hit us with the good stuff.

It's worth pointing out that this isn't the first time we've seen an "X-Men" star show up in the MCU to reprise their role — Evan Peters returns as Quicksilver in "WandaVision" – although it's later revealed as a fake-out. A la Sir Ben Kingsley, Peters is actually a normal man named Ralph Bohner. At least Professor X is actually who he says he is here — albeit a marginal multiversal variant.

The theme song is a real treat for hardcore fans, and it comes with another surprising detail buried in the end credits.

When looking at the "Multiverse of Madness" credits (and waiting for those all-important post-credits scenes) there's an interesting detail in the music section. It lists the iconic theme music as "X-Men '97 Theme." This suggests that the upcoming "X-Men '97" animated revival series will use the original theme song when it arrives on Disney+ in the near future.

It's entirely possible that "X-Men '97" is set to take place on the same version of Earth that the Illuminati live on in "Doctor Strange in the Multiverse of Madness" — or they might exist in their own version of reality. For now it's anyone's guess, but the multiverse does open up so many possibilities for franchises that weren't previously connected to the ongoing tapestry of the MCU. Obviously, there's a "Fantastic Four" movie in development at the moment — but it's not clear whether John Krasinski will reprise his role as Reed Richards from this film, or if it'll be someone completely different. The same can also be said for Patrick Stewart and Professor X whenever Marvel eventually releases a proper "X-Men" movie.

And who expected Anson Mount to return to play Black Bolt after the disastrous "Inhumans" TV series? His brief appearance is incredibly memorable, and at least he gets the full costume this time and not just a glorified leather jacket.

All this is to say: It's a great time to be a Marvel fan.