As is quickly becoming the norm for MCU Disney+ shows, What If...? ended with a bang. Episode 9 saw the newly formed Guardians of the Multiverse defeat Ultron and Doctor Strange trap the Infinity Stones—along with Killmonger and Arnim Zola—in a pocket dimension. The Watcher left Strange to be warden of those incredibly dangerous prisoners, while the rest of the Guardians returned to their own universes.
While the other Guardians seemed more than happy to return to their universes, Hayley Atwell's Captain Carter was reluctant to return to a place in time when she felt like an outsider. The Watcher assured her that she was needed there, and she agreed to once again be the "Woman out of Time."
What If...?'s conclusion is far from the last fans will see of the multiverse, as the concept seems to be the driving force in the MCU currently, and will be especially prominent in Spider-Man: No Way Home and Doctor Strange in the Multiverse of Madness. While those films will be following how the main MCU continuity connects to the multiverse, fans of the characters introduced in What If...? may be happy to know that there's reason to believe at least one of them will return in live-action in the Doctor Strange sequel.
Captain Carter, the Woman out of Time, is heavily rumored to appear in the Sorceror Supreme's multiversal romp, though it remains to be seen how much of a role she'll play in an already packed film. Let's take a look at what could link Peggy to the upcoming film and what role she could be playing in the film.
Peggy Carter, Face of the Multiverse
As usual, we'll deal with the out-of-universe stuff first. It's important to remember that there are different levels of movie-goer who see MCU films. While die-hard fans will have seen every movie and Disney+ show, there are a great many who haven't, and will only be aware of What If...? from articles and advertisements. All of them have heavily featured Captain Carter as the face of What If...?'s multiverse, so even those who haven't seen the show will recognize her and her connection to it.
Including Peggy—who also happens to be one of the most easily recognizable and distinct members of the Guardians of the Multiverse—in Multiverse of Madness would help to tie the film into the expanding extra-universal narrative the MCU is cooking up. One could argue that, outside the late Chadwick Boseman's Star-Lord T'Challa, Peggy is the What If...? character who is the most different from their mainstream counterpart.
Captain America is recognizable, and so is Peggy. Having her wield the shield immediately sends the message that fans are looking at something from a place very different from the so-called Sacred Timeline.
For fans who see Peggy appear in Doctor Strange 2 and haven't seen What If...?, it could also be a drive for them to explore the show when they may not have otherwise, which may also be a reason for the inclusion of Loki, Sylvie, and Mobius from Loki in the sequel.
Will the Watcher Intervene Again?
With the boring stuff out of the way, on to theory-crafting how and why Peggy could be showing up in Multiverse. While they were originally formed to handle the threat of Ultron, it stands to reason that Guardians of the Multiverse could be called to duty once again. While the now indisposed Sinister Strange was the first to be called on by Uatu, Captain Carter was second, and she could now be the first the Watcher requests to assist in handling whatever threat Doctor Strange and Wanda Maximoff will be battling in the film.
While there's likely not going to be much time in the film for Peggy to have a major role—especially when considering who else has been rumored to be in the film—there are plenty of ways for her to make an appearance.
A Point of Contact for Doctor Strange
The first way Peggy could appear is as a point of contact for Doctor Strange regarding the Multiverse. As Strange mentions in the trailer for Spider-Man: No Way Home, "The multiverse is a concept about which we know frighteningly little." Captain Carter's role in the film could be in advising Strange about the multiverse and the myriad threats that lie within.
It's important to remember that Captain Carter has worked with one version of Stephen Strange before, and with that version trapped as he is in his prison universe, Peggy has ended up being the member of the Guardians most able to help answer other multiversal threats. Along with that comes the theory that the film will feature Shuma Gorath as its main villain, and the tentacled Great Old One was seemingly teased multiple times throughout What If...?, though his name was never used.
There's certainly a place for Peggy to be Strange's informant regarding Shuma Gorath and part of forming a plan of action against him. Whether any reference will be made to the Watcher or to the other Guardians of the Multiverse is up in the air, though Watchers have made an appearance in the MCU before.
A Glimpse Across Universes
The other likely role for Carter in the film is a more minor one. There are, of course, time limitations in any film, and Doctor Strange in the Multiverse of Madness already seems to be hosting a wild variety of characters from across time and space. It's certainly not impossible that Hayley Atwell's live-action appearance as Captain Carter is only a short cameo sequence, perhaps when Strange or Wanda are glimpsing other universes for the first time.
Utilizing characters from What If...? and Loki in this way would be an easy way for Marvel Studios to tie the spin-offs into the wider universe of the films without using up too much screentime. To viewers of the Disney+ shows, they're nice callbacks to those series, and for more casual fans, they offer glimpses across other universes that are still grounded and recognizable.
Peggy Carter's Role in Doctor Strange 2
If we're going to consider which role in the film is more likely, it certainly looks to be the smaller, vignette one. Wanda and Strange will need a lot of screen-time, and a concept like the Multiverse will need elaboration, especially considering there will be moviegoers who haven't seen Loki, What If...? or Spider-Man: No Way Home. While the latter film will most certainly tie heavily into Multiverse of Madness, the Doctor Strange sequel will be exploring the idea of multiple universes to an even greater extent than Spider-Man.
This all points to Captain Carter's role in the film being a small one, meant more as a reference to What If...? than anything else. It's likely that the roles the characters from Loki will play will be on the same level. The film will be, at its core, focused on Doctor Strange and Wanda Maximoff, and—while other characters are interesting—this just isn't their film.
Fans can look forward to a thrill ride either way. Doctor Strange in the Multiverse of Madness will be tearing down reality in theaters on March 25, 2022.