WARNING: The following contains spoilers for WandaVision Episode 5, "On a Very Special Episode...," now streaming on Disney+.

The latest episode of WandaVision left viewers with a lot to unpack. Vision is beginning to see through Wanda's reality, their twins appear to have inherited some of their mother's powers and a visitor from possibly another universe just arrived. However, amongst all the rising tensions, the show may have dropped a subtle hint about mutants entering the Marvel Cinematic Universe. While an obvious X-Men connection came during the episode's closing moments, with Evan Peters' Quicksilver entering the MCU, Vision may have first alluded to the arrival of mutants in the episode's opening moments.

Wanda's comic book counterpart is a mutant, but her origin changed for the MCU, with Disney not having the rights to the X-Men and mutants at the time of her debut. In the MCU, Wanda and her brother, Pietro, were both Hydra test subjects, gaining powers from the Mind Stone. With Disney's acquisition of 20th Century Fox, fans have been hoping that actual mutants will enter the MCU soon; however two mutants may have already arrived with Wanda's twins, Tommy and Billy.

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"On a Very Special Episode..." opens with Wanda and Vision trying to calm their crying newborns. Vision mentions that he tried reading to Billy to get him to sleep, but, "Charles Darwin's The Descent of Man made him cry even harder." The moment is played for laughs, keeping up with the sitcom trappings of Westview, but there may be a greater significance to Vision's bedtime story.

In Marvel Comics, mutants are the next stage in human evolution, according to the likes of Magneto at leastThe Descent of Man was Darwin's work in which he applied evolutionary theory to human evolution for the first time, so it's possible that Billy's reaction to the book is a hint at his -- and Tommy's -- own mutant nature.

If this connection was intentional, it's possible it is more of an Easter egg than a conscious reaction on Billy's part, a way for the series' creators to wink at the character's comic book lineage. However, given the questionable reality of everything in Westview, it is possible there is something more going on. While this episode revealed Westview is a physical reality -- not an illusion, the true origins of Wanda's sons are still a mystery.

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Wanda's one-day pregnancy, the children's ability to age themselves at will and their apparent resistance to their mother's control has S.W.O.R.D.  and viewers wondering where the boys came from. In the comics, they were magical constructs, created by Wanda and given life by Marvel's devil, Mephisto. If they have a similarly supernatural origin in the show -- possibly one connected to whatever multiversal meddling has brought X-Men's Quicksilver to the MCU -- it is conceivable that the twins are the MCU's first mutants.

Kevin Feige has already confirmed Marvel has been discussing mutants and their future on screen, and with WandaVision set to lead into Doctor Strange in the Multiverse of Madness, viewers can certainly expect the series to begin a seismic shake-up for the MCU. After the many revelations that came in the fifth episode, it wouldn't be surprising to discover the next great leap in human evolution has already hit the MCU.

Written by Jac Schaeffer and directed by Matt Shakman, WandaVision stars Elizabeth Olsen as Wanda Maximoff/Scarlet Witch, Paul Bettany as Vision, Randall Park as Agent Jimmy Woo, Kat Dennings as Darcy Lewis, Teyonah Parris as Monica Rambeau and Kathryn Hahn as Agnes. New episodes air Fridays on Disney+.

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