While the true identity of Joe Locke’s “Teen” inAgatha All Alongremains a mystery, a wild newMCUtheory might have provided the most unexpected suggestion. Joe Locke made his MCU debut as a fan and fast friend toKathryn Hahn’s Agatha Harkness, but it’s still unclear who theHeartstopperstar is actually playing in the MCU. Dubbed “Teen” by Agatha, because he’s 16-years-old, he has joined the new Westview coven on their journey down the Witches' Road, but each new episode ofAgatha All Alongraises new questions.
There have been many theories aboutwho Joe Locke could be playing in the MCU, with the most popular, and perhaps most likely, outcome naming him as Billy Kaplan, a.k.a. Wiccan, the reincarnated son of the Scarlet Witch. Whilepromotional material forAgatha All Alongseems to have already confirmed this, there has been no mention of this in the series, so the truth could be vastly different. A new theory suggests that Joe Locke might not be playing a human character at all, but could, in fact, be theMCU’s Book of the Damned.

Joe Locke’s “Teen” Could Be The MCU’s Darkhold As A Human
Agatha All Along Has Developed The Darkhold A Great Deal
Marvel Studios first introduced the Darkhold to the MCU in 2021’sWandaVision, with the Book of Sins being in the possession of Agatha Harkness.Wanda Maximoff stole the Darkhold at the end ofWandaVision, allowing her to dream-walk in 2022’sDoctor Strange in the Multiverse of Madnessin search of her children from another reality.Multiverse of Madnessended with theScarlet Witch sacrificing herself, and destroying every copy of the Darkhold across the multiverse, but she may have spared one special version of the book.
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Agatha Harkness
The Darkhold plays an important role inAgatha All Along, and is continuing to be developed as the series progresses.Agatha All Alongepisode 3, “Through Many Miles of Tricks and Trials,” hinted at the idea thatAgatha Harkness may have traded her son, Nicholas Scratch, to acquire the Darkhold. This rumor is supported by the fact that Agatha sees the Darkhold in a crib in her hallucination caused by the Alewife’s Revenge.It isn’t too much of a stretch to suggest that the Darkhold may be anthropomorphized inAgatha All Along.
Agatha All Along’s Corpse’s Toe Tag Hints At The Body Not Being Human At All
The Identity Of Agnes Of Westview’s Corpse Hasn’t Been Revealed
The first half ofAgatha All Alongepisode 1, “Seekest Thou the Road,” featured Agatha Harkness in her Agnes O’Connor guise, inhabiting a true crime-style world, inspired byMare of Easttown.As a rogue detective, Agnes was brought in to investigate a corpse found in the woods, who the audience is led to believe is that of Wanda Maximoff. This makes sense, given the Scarlet Witch’s apparent death inDoctor Strange in the Multiverse of Madness, but there are hints this could be someone, or something, else entirely.
Every Hidden Clue Marvel Hid In Agatha’s First Episodes & Meanings Explained
Agatha All Along’s first two episodes have already included many clues and hints to upcoming storylines and major reveals in the new MCU series.
Doubt was cast on the body in the woods being a woman, and attention was drawn to “Teen’s” blackened fingers during his interrogation, perhaps suggesting they could have been one-and-the-same.The fact that theDarkhold’s library card appears as a toe-tag on the body in the morgue is perhaps the most overt clue that this body may actuallybethe Darkhold itself. It’s only through Agnes' unreliable narration that the body becomes a woman with red hair, reminiscent of the Scarlet Witch. Prior to that, it could very easily be the Darkhold in human form.

“Teen” Has Already Displayed A Huge Amount Of Power In Agatha All Along
“Teen” Helped Agatha Harkness Break Free Of The Scarlet Witch’s Spell
During his interrogation at the hands of Agnes O’Connor, “Teen” breaks out into a little bit of Latin, which he later suggests helped loosen the grip of the Scarlet Witch’s spell. Agatha was later able to strip herself of herAgnes disguises, many of which audiences will remember fromWandaVision, eventually ending up naked in her own living room, completely free of the spell.The fact that “Teen” was able to help break the Scarlet Witch’s spell is incredibly impressive, and certainly not something just a student of basic magic would be able to do.
A different version of the Darkhold was seen in Marvel Television’sAgents of SHIELD, and reappeared inRunaways, but these shows haven’t been confirmed to be canon to the MCU’s main continuity, and this Darkhold looked very different to the MCU’s current iteration.

While some have suggested that this could support the theory of"Teen" being related to the Scarlet Witch, perhaps making it easier to break her spell, the level of power needed to pull off this feat is incomprehensible.The Scarlet Witch is one of the most powerful beings in the universe, so it could be unlikely even her own son would be able to crack her spell. This may support the idea that Joe Locke is, in fact, playing a human iteration of the Darkhold, as this book has more power than the Scarlet Witch.
How Teen Can Be Both The Darkhold & Billy Kaplan In Agatha All Along
The Scarlet Witch May Have Brought Her Children To Life Upon Her Sacrifice
In an effort to avoid the complicated story ofBilly Kaplan and Tommy Shepherdfrom Marvel Comics, Marvel Studios may have simplified their origins. Upon her death inDoctor Strange in the Multiverse of Madness, theScarlet Witch may have used her last bit of magic to reincarnate her sons, Billy and Tommy Maximoff, in the bodies of two teenagers who may have met their own tragic ends. However, she also used this moment to destroy every copy of the Darkhold, so it’s very possible these spells could have been combined.
10 Biggest Agatha All Along Theories That Would Change The MCU After Its First Two Episodes
Agatha All Along has already introduced multiple hooks for fascinating theories in the first two episodes, with the potential to change the MCU.
This may have inadvertently gifted Billy Kaplan and Tommy Shepherd, who hasn’t yet been seen in the MCU, but is the reincarnated version ofTommy Maximoff’s Speed, the abilities of the Darkhold. This could have fueled “Teen’s” obsession with witchcraft and Agatha Harkness, especially since the book was in her possession for so long beforeWandaVision.Agatha All Alongstill needs to address the mystery of itsAgnes of Westviewopening, andrevealing “Teen” to actually be the Darkhold - the thing Agatha wants so much - would be game-changing.

Agatha All Along
Cast
Agatha Harkness, after the events of “WandaVision,” seeks to regain her magical powers. Joining forces with unexpected allies, including the son of an old adversary, she battles new mystical threats while uncovering hidden secrets in the magical realm.



