WandaVision Episode 7: "Nexus" Advert And Agnes' Book Explained
The Connection Between Agatha's Book And Nexus
Midway through the episode we're treated to an advert about a new kind of antidepressant called "Nexus". The narration for the ad closes out by saying "because the world doesn't revolve around you... or does it?", and with the presence of a particular book in Agatha's basement at the end of the episode, the signs all point towards WandaVision revealing Wanda to be a "Nexus Being", as she was in the comics.
Many have speculated that the book in Agatha's possession is actually the Darkhold, but that was present and accounted for in Agents of S.H.I.E.L.D. which yes, while not totally essential to the MCU timeline, still counts as canon. Either way it's not actually the Darkhold that holds the most importance to Wanda and Agatha's relationship in the comics - it's the Necronomicon, a book that Wanda reads from in the Lanning/Abnett run that reveals her status as one of the many Nexus Beings of the Multiverse.
No, this isn't the same book from The Evil Dead - and don't expect literally everything from that arc to play out on screen - but with the multiverse looming over the next phase of the MCU and Wanda's own position as a co-lead in the Doctor Strange sequel, there's a definite chance the coming episodes of WandaVision could confirm her status as a Nexus Being, and that the book in Agatha's basement is indeed the Necronomicon.
But what is a Nexus Being? Well they are extremely powerful individuals from each of the realities in the multiverse who effectively serve as the lynchpin of their own respective universes, which should put the "because the world doesn't revolve around you" line from this week's episode into a little more context. Nexus Beings also typically boast immense levels of mystic power, which is why Scarlet Witch is Earth-616's.
Lanning and Abnett's original Scarlet Witch run eventually concluded with Wanda doing battle with Master Pandemonium, as well as her own dark shadow from an alternate reality, called Lore, though it remains to be seen whether or not WandaVision could pull another villain out of its hat this late in the game.
Agatha Harkness appears to be the main villain currently, but if anyone should've learned anything from WandaVision so far, it's that jumping to conclusions isn't the soundest idea. Remember, the series also has to resolve the fate of Tommy and Billy, whose fate in the comics is indelibly tied to Mephisto. There's clearly PLENTY still going on in the little town of Westview, and while the series' endgame is beginning to take shape, don't expect to have all the answers until the final episode airs March 5th.