Warning: This article contains spoilers for Episode 5 of WandaVision.
The newest episode of WandaVision shocked millions of fans on Friday. Evan Peters reprised his role as Quicksilver, the character he made famous in Fox's X-Men series of films. This is the first time a Fox mutant has appeared in an MCU project and the door is now officially open for others to follow him in. While that surprise was enough to blow some Marvel fan's minds, it may fail in comparison to another cameo that was teased by Monica Rambeau.
Monica was discussing the steps it would take to get Westview back to normal with Darcy Lewis and Jimmy Woo when she mentioned she might know someone who would be interested in helping out. The S.W.O.R.D. agent said she knew an "aerospace engineer" who would love to take a crack at dissecting the anomaly that is Westview.
Many are theorizing on social media that this mysterious engineer, who Monica appears to text right away, is none other than Mister Fantastic. Reed Richards is one of the members of the Fantastic Four, the superhero group that will get their own film within the MCU in the next several years. Jon Watts, the director of all three Tom Holland-led Spider-Man installments, will direct the first Fantastic Four flick, but no actors are attached to the project at this time.
Game Rant recently noted the importance of another of Monica's conversations in Episode 4. While speaking with Director Hayward, it's revealed that half of S.W.O.R.D.'s astronaut training program personnel disappeared after Thanos's snap. This is also a subtle hint toward the Fantastic Four, and it now appears that there have been two setups to the group.
A Reed Richards cameo in WandaVision would be shocking, to say the least, since it would be the big reveal of the actor playing the superhero. Normally that kind of news is impossible to keep quiet and it would be quite the success for the powers-that-be at Marvel Studios. With only four episodes left to go, Reed could pop up at any time and assist the FBI and S.W.O.R.D. in helping save the people of Westview.
There are several other Marvel characters who could be the engineer Monica mentions, all of which would be surprises of their own. Other possibilities for the mysterious character include Riri Williams, James Rhodes, and Blue Marvel. No matter who ends up being Monica's pal, it will definitely be someone who will play an important part in the MCU moving forward.