Wanda Maximoff (Elizabeth Olsen) has been known colloquially as the Scarlet Witch since she first appeared in the MCU, but WandaVision took the meaning of her superhero name to a whole new level. Over the course of the show, Wanda learned the truth about her witchy abilities and finally got an emotional, in-depth origin story in the process. Still, she has plenty of magic left to master; luckily, she now has a handy education tool. After the March 5 finale, fans may be wondering: What is the Darkhold in WandaVision? It's going to play a huge role in the Scarlet Witch's future.
Warning: Spoilers for the WandaVision finale follow. At the end of WandaVision Episode 7, Wanda (and audiences) found out her nosy neighbor Agnes (Kathryn Hahn) was actually a powerful witch named Agatha Harkness, who came to Westview to find out how Wanda was able to create such an impossibly complex fake version of reality in the Hex. When she was held captive in Agatha's basement, Wanda came across a strange book, which was covered in runes and glowed an ominous orange color.
The WandaVision finale revealed this book is called the Darkhold, which contains dark magic spells like the ones Agatha had been using to mess things up in Wanda's sitcom world all season. According to Marvel lore, the Darkhold is made up of a substance from the Dark Dimension, where Doctor Strange (Benedict Cumberbatch) fought the villainous Dormammu in his titular 2016 movie.
The book also contained prophecies, including an entire chapter dedicated to an all-powerful being known as the Scarlet Witch (aka Wanda). According to Agatha, she was destined to "destroy the world." Wanda ultimately wasn't the big bad of WandaVision, and in the finale, she defeated Agatha and condemned her to live as a Westview resident (with no memory of her witchy self). After destroying the Hex and giving up her fantasy life with Vision (Paul Bettany) in the process, Wanda left Westview and took the Darkhold with her.
In a chilling post-credits scene as Wanda was seen reading the book, she suddenly heard her supposedly dead twin sons Billy (Julian Hilliard) and Tommy (Jett Klyne) screaming for help. Studying from a dark magic spellbook is never a good sign, and the Darkhold's introduction has some troubling implications for the MCU. You see, Wanda has finally accepted she's a witch and is now beginning her formal training, but learning through an evil book like the Darkhold could turn her into a true villain. It could also signal the arrival of some terrifying big bads from the Marvel comics, particularly the demon Mephisto (who plenty of viewers thought would appear in WandaVision).
The Darkhold has also appeared in the Marvel spinoff series Agents of S.H.I.E.L.D., where it was used to create things by drawing energy from other dimensions. It makes sense that Wanda would try to draw energy from another universe to try and rescue her kids (who may very well be trapped in another world), especially since the MCU seems to be introducing multiverses in Spider-Man: No Way Home and Doctor Strange 2. Wanda will be one one of the main characters in the latter, and there's a chance that, through her possible attempts to use dark magic to reunite with her twins, she could end up becoming the movie's villain.
Regardless of whether Doctor Strange and the Scarlet Witch become allies or enemies, the Darkhold is bound to play a seriously ominous new role in the MCU.