Agatha All Along Dropped A Cheeky Mephisto Easter Egg Only Hardcore Marvel Fans Noticed

This post contains spoilers for "Agatha All Along."

When "WandaVision" dropped roughly three years ago, the internet was abuzz with speculations about a certain fiery Hell-Lord from the Marvel comics. "It's Mephisto, confirmed," was a phrase that often cropped up in theory-crafting and discussion threads, and these speculations did warrant credit at the time, as Mephisto is featured in the source material that "WandaVision" heavily drew from. Unfortunately, this did not pan out, although it birthed a meme in the process: in almost every MCU entry, existing or yet to be realized, Mephisto's demonic specter looms large, as this extradimensional entity has evolved into a fan-favorite "mastermind" behind every conspiracy or dark plot. The first two episodes of "Agatha All Along" — a series that takes place after the events of "WandaVision" — even make a tongue-in-cheek nod to Mephisto while laying out Agatha's path to regaining her powers. This mostly seems like a fun little reference and does not necessarily hint at Mephisto's actual involvement.

... Or does it?

Well, it is too early to say anything, but let us set the stage for this Easter egg before we dive into what it means. Episode 1 begins with Agatha/Agnes (Kathryn Hahn) working as a detective in a crime drama/noir storyline (in her attempts to adjust to the chaos magic-infused reality of Westview), but the presence of Rio Vidal (Aubrey Plaza) and The Teen (John Locke, whose character remains unnamed so far) force her to come to terms with her core self. A simmering tension is hinted at between Agatha and Rio, a Green Witch, but it is revealed that the two share a long and complicated past, with their close relationship souring after some point. The exact nature of the falling-out is unknown, but their interactions are decidedly charged, hinting at a now-contentious bond that had once been deeply passionate and loving.

During their first physical altercation in episode 1, an allusion is made to a "black heart." Specifically, when Agatha accuses Rio of not having a heart, she says, "Yes, I do. It's black and it beats for you." But what does this mean?

It was Mephisto all along (sort of)

At first glance, this exchange sounds like a standard ex-lover's spat, but the phrase "black heart" is referenced again in episode 2, when Lilia (Patti LuPone) divines four names for Agatha's coven for the Witches' Road summoning. The fourth name is concealed from us at the beginning, although Agatha seems uncomfortable with its implications, especially after she sees a raven, a rat, and a wolf throughout the day. Later, Lilia reveals that the fourth name on the list is just a black heart, which, when contextualized against Rio's conversation with Agatha, would mean her. This makes sense from a ritualistic standpoint, as the fourth coven member needs to be a Green Witch, just like Rio.

However, the term "black heart" is also a sneaky little reference to Blackheart, who is ... wait for it ... Mephisto's "son" in Marvel's comic books. First appearing in 1989's "Daredevil" #270, Blackheart was created after Mephisto gravitated towards the dark aura of Christ's Crown, New York, using the evil energy accumulated to fuel the birth of a son. Blackheart evolved into as much of a menace as his father, tormenting the likes of Daredevil and Spider-Man, but failing to corrupt them. Blackheart looks similar to Mephisto, apparently smells like burnt roses (!), and has often teamed up with his father to fight superheroes over the years. In terms of his powers, Blackheart possesses standard super-strength, speed, and agility, and can teleport, mind control, and shapeshift.

Will Blackheart jumpscare us in one of the trials inside the Witches' Road? It is, once again, unlikely, but the mystery surrounding Rio's motivations and allegiances leaves us with much to ponder, as anything can happen in the realm of magic — as the roads there are dark and dreary, housing many entities.

The first two episodes of "Agatha All Along" are currently streaming on Disney+.