WandaVision introduced viewers to the Darkhold, described as "The Book of the Damned" - here's everything you need to know about it and what it means.

WandaVision episode 9 ended with Scarlet Witch in possession of a mystical tome called the Darkhold - here's everything you need to know about it. When Wanda Maximoff entered Agatha Harkness' mysterious sanctum, she found herself in a place where she was vulnerable, encircled by mysterious runes that robbed her of her magic. But Agatha's basement was dominated by a mysterious book, one that crackled with ominous eldritch power.

This book of dark magic may well have been set up by Doctor Strange back in 2016, when Stephen Strange attempted to read some of the books in the Ancient One's private collection. Although the film focused on the Book of Cagliostro, attentive viewers noticed one of the books was missing. Given the Ancient One's collection was of books she considered too dangerous for any but the Sorcerer Supreme or the most accomplished members of the Masters of the Mystic Arts to read, this suggested a very powerful tome had vanished from Kamar-Taj. This naturally led to some speculation Agatha's book could actually be the Darkhold, the most famous book of magic in Marvel Comics.

That has now been confirmed, with Agatha Harkness explicitly naming her book as the Darkhold in WandaVision episode 9. But what is the Darkhold, which she described as the "Book of the Damned?" Here's everything you need to now.

The Darkhold Is Marvel's Most Dangerous Magical Book

In order to understand the Darkhold, you first have to be familiar with the ancient history of the Marvel Universe. In Marvel lore, the primordial Earth was no paradise; rather, it was ruled by powerful beings known as the Great Old Ones or the Elder Gods. Although some such as Gaea were good, others burned with a lust for power, and they soon learned they could consume the magic of others. And so Earth became a place of turmoil and war, with the most predatory Elder Gods becoming ever more powerful. One of the greatest of these beings was Chthon, the first master of dark magic, who learned the secrets of a forbidden sorcery called Chaos Magic. In the end, though, the majority of the Elder Gods were successfully banished to other dimensions.

Chthon left behind him a dark gift for humanity, a collection of scrolls that served as a conduit for his power and would one day allow him to return to Earth. The scrolls were transcribed on to stone and later on to parchment, when they were bound together in a book of dark magic known as the Darkhold. Chthonic cultists called Darkholders guarded the Darkhold, seeking to use its arcane power to restore their evil master to this plane of existence. In the comics, the Darkhold is the source of some of the most horrific supernatural evils, for its pages have unleashed vampires and werewolves upon the world. Other sorcerers have routinely examined its pages, with the Book of Cagliostro containing copies from pages of the Darkhold. It has gained so many descriptive names, including the Book of Sins and the Book of the Damned.

Scarlet Witch Now Possesses The Darkhold

Agatha Harkness hinted there was some sort of connection between the Darkhold and the Scarlet Witch, revealing the Book of Sins contains a full chapter dedicated to Scarlet Witches. This makes sense; in the comics, Wanda Maximoff was chosen by Chthon to wield the power of Chaos Magic, and every time she used this power she damaged the fabric of reality and made a Chthonic invasion of this dimension easier. Agatha's horrified reaction when Wanda unleashed the full power of the Scarlet Witch suggests the same will be true in the MCU as well, with the ancient witch declaring Wanda had no idea what she had just done.

The Darkhold is now in Scarlet Witch's possession, and she is clearly using it to learn sorcery. Unfortunately this is probably a mistake, because the Darkhold is no mere book; it is an object of dark magic, and the spells it contains possess the power to corrupt the soul itself. In Doctor Strange, Stephen Strange learned the Book of Cagliostro always put the warnings after the spells, meaning he had no idea his experiments with the Time Stone risked destroying the fabric of space-time; the Darkhold, however, would not contain any warnings at all. WandaVision's post-credits scene suggested Wanda has already learned a lot from the Book of the Damned, copying Stephen Strange's astral reading trick; but these lessons are most definitely unsafe. Given Elizabeth Olsen's Scarlet Witch is confirmed to have a major role in Doctor Strange in the Multiverse of Madness, it's reasonable to assume the power she gains from the Darkhold ultimately fractures reality. Presumably Chthon will be the villain of Doctor Strange 2, although it's possible the character will be blended with others of the Elder Gods, such as Shuma-Gorath, who has a more striking visual design.

The Darkhold Could Be The Source Of Vampires In The MCU

Meanwhile, Marvel is finally working on a Blade movie, starring Mahershala Ali as the MCU's vampire hunter. Importantly, in an interview with Rotten Tomatoes Marvel Studios president Kevin Feige suggested there would be a direct link between Doctor Strange 2 and Blade. "We have, for years, wanted to find a new way into Blade," he teased. "We love that character. We love that world. Now, with Doctor Strange and the supernatural elements coming into the MCU, it felt like we could definitely start exploring that..." Feige's comment appears to suggest Doctor Strange 2 will setup Blade by having the world flooded with dark magic, with supernatural enemies crawling out of the woodwork - and, given vampires were created by the Darkhold in the comics, it's not hard to see how that could lead to the introduction of Blade.

Intriguingly, one of the most important Darkhold stories in the comics was Doctor Strange #60, which saw Stephen Strange, Scarlet Witch, and Monica Rambeau work together against Chthon's acolytes and vampiric legions in order to prevent the power of the Darkhold being abused. WandaVision introduced Teyonah Parris as the adult Monica Rambeau, and even granted her the powers she needed to help protect the Darkhold. It's entirely possible Doctor Strange in the Multiverse of Madness will draw upon this story.

The MCU's Darkhold Is Bad News For Agents of SHIELD

There is, however, one bit of bad news for Marvel fans. The design of the MCU's Darkhold in WandaVision is like nothing what's been ever seen before - in fact, visually it's more akin to the Iron-Bound Books of Shuma-Gorath than to its traditional comic book version. It also looks nothing like the Darkhold seen in Marvel's Agents of SHIELD, another piece of evidence suggesting the popular Marvel Television show - which finished last year - should not be considered canon to the mainstream MCU. Marvel Studios could have chosen to follow the same design in order to establish a narrative throughline, but they chose not to, and that decision is sadly significant.

More: WandaVision's Post-Credits Scenes Set Up 3 New MCU Movies & Shows