UPDATE: Avengers 3 is out! Read our explanation of Infinity War's Soul Stone location!

Black Panther may have expanded the world of Marvel Cinematic Universe, but there's one big question about the franchise's future it leaves completely - and surprisingly - unanswered: where is the Soul Stone?

The next film in the MCU is Avengers: Infinity War, which will see Mad Titan Thanos try and collect the six Infinity Stones in a bid to attain ultimate power in the universe. Most of the stones have been the central MacGuffins in previous movies, but the last - the Soul Stone - has been conspicuously absent. It was expected to turn up in Black Panther, yet it's hardly a spoiler to say it doesn't. And so now we're left with one giant orange hole at the center of the 18-movie-strong franchise.

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Today we're going to try and crack the case. With pretty much all the evidence we can possibly have ahead of Avengers: Infinity War, here's where we think the Soul Stone could be.

This Page: The Soul Stone Mystery Explained

The Mystery Of The Last Infinity Stone

Infinity Gauntlet Collector Seeking Stones

This is the story of the MCU. Marvel started introducing the Infinity Stones in Thor's post-credits scene (where it was revealed Nick Fury has acquired Captain America: The First Avenger's Tesseract), and explicitly building towards an Infinity Gauntlet arc since the Thanos' reveal in The Avengers' mid-credits scene.

The Infinity Stones are gems of near unlimited power created in the Big Bang from six singularities that pre-date time itself. Independently they each have their own powers (although in the movies have been somewhat interchangeable MacGuffins), but when brought together will allow the user near-Godlike autonomy over the universe. Thus far we've been introduced to five of the Infinite Six: the Tesseract in The Avengers (Space Stone); Loki's scepter in Avengers: Age of Ultron (Mind Stone); the Aether in Thor: The Dark World (Reality Stone); the orb in Guardians of the Galaxy (Power Stone); and the Eye of Agamotto in Doctor Strange (Time Stone). One, however, has been missing: the Soul Stone.

Read More: Where Are The Infinity Stones Now?

Theories have abounded for where it could be. Many of these centered around Thor: a long-standing expectation was that Heimdall either was himself or otherwise in possession of the Soul Stone, mainly due to his all-seeing power and its associated orange glow. Another, alt-Asgard theory suggested Odin was in possession of the Stone, and that his death in Thor: Ragnarok would see that power transfer to Hela (and, as a pivotal trailer scene was cut, may have initially been the case). When Thor 3 disproved that, all eyes turned to Wakanda; the only remaining film before Avengers: Infinity War would put the Stones front and center, it surely had to appear in Black Panther. And yet, nothing. Where is the Soul Stone?

What We Know For Certain About The Soul Stone

The Infinity Gauntlet full of Infinity Stones

Theories have been so varied about the Soul Stone mainly because we know so little about it. From the films, all we really have is that it's orange. Assuming it's going to share some properties of the comic book Soul Gem (something that hasn't always been the case for the Infinity Stones), its powers will be some of the most out there, allowing the wielder to look into and collect other people's souls.

A few things regarding the Soul Stone can be gleaned from promo material for Avengers: Infinity War, however. It's the central gem in Thanos' Infinity Gauntlet per repeated images of his with the full set, and he won't get it until later on in his quest for the stones; from the trailer we see he gets the Power Stone and Space Stone first, and a behind-the-scenes video showing a semi-complete Infinity Gauntlet suggested next up would be the Mind Stone and Reality Stone.

So: the Soul Stone orange; it has powers unlike anything we've seen in the MCU up to this point; and it likely won't factor into Infinity War until the latter half (if not Avengers 4). How does this help us?

The Soul Stone Isn't In Black Panther

That the Soul Stone could be in Black Panther in many ways came about due to a lack of options - when it wasn't in the cosmically-minded Guardians of the Galaxy Vol. 2 or Thor: Ragnarok, it was literally the only other possibility. However, the suggestion that the vibranium source of the Wakanda's power (and its hero King) is actually Soul Stone has really caught on since. It would explain how a space metal is able to gift superpowers and provide dreams to another, astral realm, while in the Infinity War trailer, it's evident that Wakanda will be the staging ground for a massive battle between Earth's Mightiest Heroes and Thanos' Outriders. There are several reasons why Thanos would attack the secluded nation, but the simplest and most elegant was that it's the location of the final stone.

Read More: Avengers: Infinity War Trailer Teases Where The Final Stone Is

Of course, as we've already established, that's not even alluded to in Black Panther itself. Now, there's nothing to explicitly say the vibranium meteorite at the heart of Wakanda isn't housing the Soul Stone, but there's conversely no evidence to say it even could be. Another big notch against it is the color; throughout the film, the associated color for not just Shuri's tech but the vibranium that powers it is purple, a full traversal of the color wheel away from the Soul Stone's orange. The only orange on show in the film is Killmonger's golden suit, and that feels more done to contrast T'Challa's than it does hint at anything deeper.

In the absence of proof, there's also been an alternative suggestion for why Thanos would attack Wakanda. The Super Bowl TV spot showed an injured Vision after the Black Order attack him trying to steal the Mind Stone. If he still has the gem and - as merchandise suggests - he's taken to Wakanda, that's all the motivation needed to lead an assault on the city.

The Soul Stone Could Still Be In Wakanda, However

Avengers Infinity War Black Panther Leads Wakandans to Battle

However, none of that means a Wakandan stone is out of the running, just that it wasn't in the country's debut. And, being pragmatic, putting it in Black Panther could have really upset the narrative; it's a movie with a very grounded approach in African tradition, and to put a bit of space magic at its center risks knocking the whole thing off. Besides, even it was well integrated, the film mostly avoids overt MCU setup of any form, and as the Soul Stone is the biggest question in the fandom presently, there's no way it wouldn't distract.

It could still be there, just hidden. Indeed, the color difference can easily be discredited given Marvel already pulled a similar (albeit potentially retconning) trick with the Mind Stone; it appeared blue in The Avengers, but cracked open to reveal a yellow gem in Age of Ultron. It's entirely possible at the heart of the purple meteor lies an orange stone. That's something Infinity War's tie-in LEGO sets corroborates; each of the six models comes with one of the Stones, and the Soul Stone is hidden in the Wakandan fight kit. Now, this is merchandise - and notoriously misleading LEGO at that - so must be taken with a pinch of salt, but it's an odd matchup if it is elsewhere.

Read More: Black Panther May Reveal The Final Infinity Stone

We're dealing with a lot of vague notions here, but as it stands it still feels rather probable that the Soul Stone will still be Wakanda after all, and that it didn't appear in Black Panther simply because T'Challa himself is unaware. Although that's not the only possibility.

The Planet from Avengers Infinity War

How Will The Soul Stone Be Brought Into Avengers: Infinity War?

However, assuming that the Soul Stone isn't in Wakanda and that Thanos is only attacking because of Vision, where else could it be? What we know is that it's likely to be one of the last stones Thanos acquires, so it'll come later on in the film. This is getting into unclear territory speculation-wise, but we can nail some facts down.

Wakanda doesn't look to be the final battleground in Infinity War. Both the SDCC trailer and first teaser appeared to tease some sort of barren rocky landscape - perhaps the planet from the start of the trailer - one that was also seen in the Day 1 production video and has been teased (again) by the backdrop of the LEGO sets. Bringing all the information together with a fair pinch of salt, we can conclude that the ending of Avengers 3 sees the Avengers and Guardians of the Galaxy team up and take the battle to Thanos' home turf. This last-ditch effort needs some goal, and the final Infinity Stone is as good a target as any.

Essentially, if the Soul Stone isn't in any known location, it's presumably being saved as the actual MacGuffin of Infinity War itself. That is, of course, assuming it's in Avengers 3 at all.

Related: Black Panther's Post-Credits Scenes Explained

Is The Soul Stone Being Saved For Avengers 4?

Everything so far has been working on the assumption that, by the end of Avengers 3, Thanos has all six of the Infinity Stones in his possession. This is definitely possible - if we are getting the culmination of the MCU's near-two-dozen movie arc, they're not going to scrimp on spectacle - but the actual argument hinges on this being a direct copy of one of the many comic inspirations - Infinity Gauntlet or Infinity - and a little-evidenced expectation the first film of the back-to-back Avengers 3 & 4 will end with Thanos doing his iconic finger snap. Stripping that away, we have little to go on. It's possible that while Infinity War is the collection movie, it won't end with a complete set; after all, that behind-the-scenes gauntlet wasn't complete.

We know very little about Avengers 4 - by Marvel's design to keep Infinity War spoilers a secret - but thanks to set photos we've been able to deduce it's a time travel film. Of course, even that doesn't provide much; why are some or all of the Avengers are jumping through various timelines in the first place? A prevalent theory has it related to an attempt to stop Thanos' dominance and messing with the timestream, but an alternative view is that he doesn't assemble the full set of six stones and that all of that timey-wimey meddling is a quest to get the Soul Stone.

This is, naturally, rather groundless, but would fit with the notion the Soul Stone is being held back for a reason. Although there is one final, more comic-skewed possibility.

Adam Warlock And The Soul Stone

Adam Warlock Cocoon in Guardians of the Galaxy Vol 2

In the comics, the Soul Stone is heavily linked to Adam Warlock; it was essential to resurrecting "Him" after his initial debut and was his entrance point into the original Infinity Gauntlet arc. As with Thanos getting all the stones, this comic importance has led to an expectation of Adam Warlock having some part to play in the big screen version - possibly bringing the Soul Gem with him. That's frankly looking unlikely at present, although isn't totally impossible.

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Adam was introduced into the MCU in Guardians of the Galaxy Vol. 2's mid-credits scene, created by Ayesha as a weapon of Sovereign to take down the Guardians of the Galaxy. Pointed as it may be, which movie the stinger was setting up is still unclear; James Gunn stated that Adam Warlock won't make his proper bow in Infinity War, but he's neither been able to confirm him for Guardians of the Galaxy Vol. 3. The way the director tells it, he pushed Kevin Feige to include the character, indicating no short-term plans, but it's entirely possible some or all of this is a smokescreen.

Rationally, Warlock being in Avengers 4 (a film we've had no denial of his presence in) feels unlikely - there's been no casting rumors and Guardians of the Galaxy Vol. 3 feels a much more cohesive fit - but it must be mentioned the glowing orb above his birthing pod is noticeably similar to the Soul Stone as seem in Thanos' gauntlet in promo images. That would be some very classic Marvel foreshadowing.

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It is, in no uncertain terms, a shock that the Soul Stone remains such a mystery with Avengers: Infinity War less than three months away from release; it's equally likely that Marvel's secretly set it up as they are holding it back for an important role down the line. All we can say with certainty is they must have a reason to be keeping it hidden - one we'll finally find out in May.

Next: Black Panther's Ending Explained In Detail

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