Why a surprise guest in this week’s ‘WandaVision’ could be a game-changer for the MCU

This story includes spoilers from the fifth episode of “WandaVision.�

“WandaVision� sure knows how to keep its viewers on their toes.

The latest episode of the Disney+ series — aptly titled “On a Very Special Episode…� — concludes with a very special surprise appearance by Pietro Maximoff, Wanda’s brother. Except, as Darcy notes while observing the scene on her monitor, it was not exactly the same Pietro that had been previously introduced in the Marvel Cinematic Universe.

Until now, the MCU’s Pietro has been played by Aaron Taylor-Johnson. The speedster, who with Wanda had been recruited in the fight against the Avengers, ultimately died a hero in “Avengers: Age of Ultron� (2015). As “WandaVision� has shown in recent episodes, it’s a loss Wanda is still grieving.

The Pietro Wanda greets at her door at the end of “WandaVision’s� fifth episode, however, is portrayed by Evan Peters. In the scene, Wanda and Vision seem to be taken aback at his sudden appearance and apparent “recasting.�

But fans of Fox’s “X-Men� franchise will recognize Peters for his role as the mutant Quicksilver, a.k.a. Peter Maximoff. Introduced in 2014’s “X-Men: Days of Future Past,� this Quicksilver is another version of the same Marvel comic book hero that the MCU’s Pietro is based on. Peters last portrayed the character in 2019’s “Dark Phoenix.�

Pietro versus Peter

In the comic books, Wanda/Scarlet Witch and Pietro/Quicksilver are twin mutants who eventually learn their father is Magneto, a character that over the years has more often been an X-Men villain than not. Before their familial ties were revealed, Scarlet Witch and Quicksilver were part of Magneto’s Brotherhood of Evil Mutants. When the twins eventually switch sides, they choose to join the Avengers.

This means Scarlet Witch and Quicksilver were associated with both the “X-Men� and “Avengers� comic book titles, which is not an issue in the comics but becomes more complicated when licensing agreements come into play. Until recently, different companies owned the film rights to the two teams. Ultimately, this meant Fox’s “X-Men� movies could include Quicksilver/Peter as long as there was no mention of the Avengers, and the MCU movies could include Pietro as long as there was no mention of mutants or the X-Men.

Disney’s acquisition of Fox in 2019 changed that. Fox’s separate “X-Men� franchise is no more, and Marvel Studios is free to incorporate any of those characters into the MCU.

What does this appearance mean?

Peters’ appearance as Pietro on Wanda’s doorstep might be anything from a fun easter egg to foreshadowing of what’s to come on the show and in the MCU more broadly.

The concept of a multiverse — or the concurrent existence of a group of multiple observable universes — is not new or unique to Marvel (see “Spider-Man: Into the Spider-Verse�). And it’s already known that events of “WandaVision� will help set up the upcoming “Doctor Strange and the Multiverse of Madness.�

Perhaps Wanda pulling in the “X-Men� franchise’s Peter — the Pietro of another universe — into her world in Westview is a precursor to how the multiverse will come into play in the MCU.

Pietro’s appearance could also be in tribute to Brian Michael Bendis and Olivier Coipel’s 2005 series “House of M,� one of the comic book storylines that seems to have inspired parts of “WandaVision.� In the eight-issue story, Wanda’s overwhelming grief leads her to use her powers to create an alternate reality where many characters are living out their dreams. It’s eventually revealed that Pietro was the one who suggested she use her power in that way — because he was afraid the Avengers/X-Men, who had deemed the grieving Wanda a powerful threat, would kill her.

The end of the “House of M� storyline also had important repercussions for the X-Men and all mutantkind on Earth. Wanda was shown to have the ability to take away (and later restore) mutants’ powers. Perhaps “WandaVision� will offer hints as to how mutants and the X-Men can be incorporated into the MCU.

Then again, as “WandaVision� has shown, Wanda can transform existing things into something else — see the kevlar in Monica Rambeau’s outfits — and affect people’s understanding of their own identity to play the characters in her sitcom.

Perhaps this new Pietro is just some guy from Westview who Wanda “recast� to play Pietro when she needed him, and Peters’ appearance is a tribute to sitcoms past that have recast principal characters.

That said, the introduction of Wanda and Vision’s twins seems to indicate that things are not that simple. Viewers will just have to keep tuning in to see how events unfold.