How 'Agents Of S.H.I.E.L.D.' Connects To 'Doctor Strange'

For the most part, Marvel's movies and Marvel's shows operate independently of one another. Characters rarely move between them, and it's certainly possible to enjoy one side without paying any attention to the other. Still, they all technically belong to the same continuity, and every once in a while, they like to remind you of that fact. Like right now. With Doctor Strange approaching theaters, Agents of S.H.I.E.L.D. has revealed a mystical link to the movie. 

A couple of episodes ago, Agents of S.H.I.E.L.D. dropped a reference to something called the Darkhold. Then the most recent episode (season four, episode four, "Let Me Stand Next to Your Fire") shed a little more light on the item. Eli (José Zúñiga) explains that Lucy, the ghost that's been making trouble this season, got that way after a failed attempt to build a quantum particle generator that can create matter out of nothing. Now she and her fellow spirits are after the Darkhold, an artifact that, according to Coulson, not even Red Skull, Daniel Whitehall, or Nick Fury have been able to find.

In the comics, the Darkhold (a.k.a. the Book of Sins) was written billions of years ago by a demonic entity known as Chthon. It's perhaps the most potent book of black magic ever created, and one of the most dangerous mystical items in the Marvel universe; among other things, it's behind the creation of werewolves and vampires. Naturally, all that power comes at a very steep cost to mortal users, like one's own soul.

First introduced in the comics in 1972, the Darkhold has popped up several times over the years in conjunction with several key Marvel characters — including Stephen Strange, who came into possession of it at some point. It's surely no coincidence that the ancient mystical artifact is cropping up in the show just as the films gear up to introduce Strange for the first time on the big screen. The plot of Doctor Strange involves the villain, Kaecilius (Mads Mikkelsen) stealing forbidden books from his former mentor, the Ancient One (Tilda Swinton). Could the Darkhold be among those titles?

It's also worth pointing out that the Darkhold has ties to some other Marvel characters who have not yet joined the Marvel Cinematic Universe, like Conan the Barbarian, Red Sonja, and Blade. Depending on how things pan out, the book could serve not just as a link between Doctor Strange and Agents of S.H.I.E.L.D. but also, maybe, potentially, someday, a way to set up some other characters to join the franchise. In the meantime, S.H.I.E.L.D.'s Darkhold plot looks like it's far from over, so we may learn much more about its role in the MCU in the coming weeks.