The best (and weirdest) theories about Avengers: Infinity War’s biggest mystery

Where oh where is the Soul stone?

War Machine (Don Cheadle), Winter Soldier/Bucky Barnes (Sebastian Stan), Black Widow/Natasha Romanoff (Scarlet Johansson), Captain America/Steve Rogers (Chris Evans), Hulk (Mark Ruffalo), Okoye (Danai Gurira), Falcon (Anthony Mackie) and Black Panther/T'Challa (Chadwick Boseman) in Avengers: Infinity War (Marvel, HF)

With just a few weeks to go until the release of Avengers: Infinity War, one burning question remains. No, not “how on Earth will Ant-Man’s new film fit in between two interconnected Avengers films, unless he nips out for his own adventure mid-battle?” – we’re wondering where oh where on Earth, in outer space or the nine realms is the Soul stone.


In case you haven’t been paying attention, the Soul stone is the last of a group of reality-altering gems called Infinity stones with different effects that have appeared throughout the Marvel movies, with all six sought by baddie Thanos (Josh Brolin) for his evil schemes in Infinity War next month.

So far, we’ve seen five stones in action, but the location of the sixth remains a mystery. We had our own theory last week, but after a few of you got in touch with counter-proposals of your own we thought it was high time to collect all the best theories about the Soul stone’s location before the film comes out and reveals it’s just glued to the back of Captain America’s shield or something.

So to begin: could the stone be….

In Wakanda?

Marvel, HF

We wrote about this in some more depth last week, but the basis of this theory comes from the fact that The Black Panther’s (Chadwick Boseman) home nation features heavily in the Avengers: Infinity War trailer as the location of a major battle. Why would Thanos attack there if it didn’t have something he wanted?

Meanwhile, many fans have pointed out that some of the effects of the Heart-shaped Herb (the plant that gives T’Challa his abilities when he drinks it) are similar to those of the comic-book Soul stone, which was supposedly able to create an idealised parallel dimension rather like the realm where T’Challa and Killmonger (Michael B Jordan) visit their ancestors.

Fans have also noticed that Thanos’ own name has in a way predicted each of the stones’ locations of the years, and the Heart-shaped Herb fits nicely into this pattern.

T= Tesseract (the energy-supplying cube which comes from the Space Stone)

H= TBC, could be Heart-shaped Herb

A= Aether (the alternate form of the Reality Stone from Thor: The Dark World)

N= Necklace (ie, when the Time Stone was on the chain of the eye of Agamotto in Doctor Strange)

O= Orb (which the Power Stone was hidden inside in Guardians of the Galaxy)

S=Sceptre (a weapon containing the Mind Stone wielded by Loki in the first Avengers film)

It could all be coincidence though, as some of the other theories are also pretty compelling…

Heimdall has it

Idris Elba as Heimdall in Thor: Ragnarok (Marvel, HF)
Idris Elba as Heimdall in Thor: Ragnarok (Marvel)

If the “Thanos’s name spells out the stones’ location” theory does turn out to be true (given how laboured some of the connections are, it could just be a weird coincidence), there’s also another candidate for an H-themed Soul stone hiding place – Idris Elba’s Asgardian bouncer Heimdall, last seen fleeing the ruins of the Norse realm with Thor (Chris Hemsworth), Loki (Tom Hiddleston) and the rest of their people.

You see, Heimdall’s all-seeing orange eyes exactly match the hypothesised colour of the missing Soul stone (it’s too complicated to explain why we can know its colour but basically, it’s been confirmed), and his ability to locate and communicate with anyone in the world somewhat ties into some of the Soul stone’s other comic-book abilities including telepathy and connection to people’s souls.

Now, given that this ability seems to be part of Heimdall it’s also possible that he was merely empowered by the stone rather than actually possessing it – Avengers Scarlet Witch (Elizabeth Olsen) and Quicksilver (Aaron Taylor-Johnson) were given their own abilities from the Mind stone, after all – but this might still end up granting us a clue as to where the stone really is.

In which case, the answer could be that…

We’ve already seen it in the trailer

Now this is an interesting one. Some fans have been speculating that we could have actually seen the Soul stone in the opening moments of the Infinity War trailer, in the form of an enormous planet hanging in space.

This sounds a bit farfetched, we know, but the planet seems to be the right colour (again, that pesky orange), and other scenes apparently set on its surface (we see Thanos, Iron Man, Nebula and others battling in a dusty orange background) bear a striking resemblance to “Soul World,” the alternate dimension where the comic-book version of the gem traps the souls it has captured.

Karen Gillan as Nebula in Avengers: Infinity War (Marvel, HF)
Karen Gillan as Nebula in Avengers: Infinity War (Marvel)

It’s possible the movie version of the Soul stone will simplify this idea to just make it a planet rather than an alternate dimension, and we’ll see our heroes fighting for their lives on it next month – and if you think this sounds a little silly, well, official tie-in stories seem to be hinting that it could be true.

In the latest in a series of comic-book prequels to Infinity War, we see Benedict Cumberbatch’s Doctor Strange chatting with colleague Wong (Benedict Wong) about the Infinity stones, and how the Soul stone could be the “biggest threat of them all” due to its greater power.

A series of panels from Infinity War's prelude comic (Marvel, HF)
A series of panels from Infinity War’s prelude comic (Marvel)

During their chat, we get a glance at the book Wong’s reading on the topic, which is illustrated with, you guessed it, a few slightly yellowy-orange planets that definitely could be depicting the same world glimpsed in the trailer. Starting to look a little less out-there as a theory now, eh?

It’s HIM!

Adam Warlock's cocoon from Guardians of the Galaxy Vol. 2 (Marvel, HF)
Adam Warlock’s cocoon from Guardians of the Galaxy Vol. 2 (Marvel)

At the end of Guardians of the Galaxy vol 2 director James Gunn teased the future appearance of Adam Warlock, a character from the comics designed to be a “perfect” human and who in the movies appeared to be created by The Authority’s leader Ayesha (Elizabeth Debicki) as revenge against the Guardians (in a post-credits scene she’s seen naming him “Adam” as he waits inside a cocoon very like the one he emerges from in the comics).

Anyway, the reason this is relevant is because in the comics Adam is often associated with the Soul stone (or the Soul gem as it’s known there), which he owned and used to transform his enemies and occasionally trap souls, as well as living within its alternate Soul World dimension (which in recent iterations has looked rather like the orange world we see in the trailers).

Perhaps in Infinity War, Adam’s traditional tie with the Soul stone will be replicated, before Thanos steals it from him and uses it to enact his evil plans. Sure, Warlock hasn’t been introduced much apart from that one post-credits scene, but we’re sure they could build him up in the time they have.

Adam Warlock’s involvement also ties in with the theory about the stones’ hiding places spelling out Thanos’ name, incidentally – one of his most famous aliases in the comics is as Him, paired with a female counterpart called Her.

Hulk has it

Mark Ruffalo's Hulk in Thor: Ragnarok (Marvel, HF)
Mark Ruffalo’s Hulk in Thor: Ragnarok (Marvel)

Leaked toy and Lego designs for Infinity War have shown Mark Ruffalo’s Hulk using the Soul stone as a weapon – so could this be a spoiler for the film?

Given that Lego sets and action figures sometimes take some pretty severe diversions from the movie storylines, we’re not so sure – we can’t help but recall some Lego Mandarin battle vehicles released for Iron Man 3 that Ben Kingsley definitely didn’t use considering he was playing an actor rather than a real terrorist – and even if it is true that Hulk interacts with the stone at some point during the film, it’s not so much of a clue as to where it will be found.

Still, as I’m sure you will have noticed, we have here another “H” candidate to complete the Thanos name game. How exciting.

Iron Man is the key

Robert Downey Jr as Iron Man/Ton Stark in Avengers: Infinity War (Marvel, HF)
Robert Downey Jr as Iron Man/Ton Stark in Avengers: Infinity War (Marvel)

To take this discussion in a completely different direction, some leaked artwork from tie-in book IncrediBuilds: Marvel: Infinity Gauntlet Deluxe Book and Model Set was recently leaked and had fans wondering – what if IRON MAN is the key to this whole mystery?

You see, in the new artwork we see all six stones depicted with various heroes refracted within them, and in five of these stones the character at the centre of the gem is the one who first encountered it in the movies.

So we have the Power stone with Star-Lord (Chris Pratt) from Guardians of the Galaxy, the Space stone (aka the Tesseract) with Captain America (Chris Evans) from The First Avenger, the Reality stone with Thor (Chris Hemsworth) from The Dark World, the Time stone with Doctor Strange from his solo film and the Mind stone with Paul Bettany’s Vision, following its melding with his body in Avengers: Age of Ultron.

The Soul stone, meanwhile, is with a character few would have connected to it – Iron Man/Tony Stark. So could the Soul stone be something to do with him?

Well, maybe. Fans are already speculating that Tony may have been brought to life with the Soul stone, especially after his father Howard (Dominic Cooper/John Slattery) told him that “my greatest creation… was you” in Iron Man 2. The H of Howard would also tie in with the “THANOS” theory, if you’re keeping score.

Alternatively, Infinity War could be taking a page out of an Ultimate Marvel storyline, where it’s revealed that one of the Infinity stones is hidden inside Tony Stark’s brain for… some reason. Later in the same storyline, after the stone is cut out of him and he’s left for dead, Tony uses one of his remote-controlled armours to take one of the stones, revive his body and give him new powers over technology, which… could be something that happens?

Then again, it could be that Tony doesn’t HAVE the Soul stone, exactly, but he’ll be central to its appearance in the new film, perhaps trying to use it to power a special suit of armour that can properly go toe-to-toe with Thanos after already finding it elsewhere. If nothing else, it would look Very Cool.

OR they just had to shoehorn Iron Man in somewhere and that corner seemed as good a place as any. All fine options.

All of the above

Josh Brolin as Thanos in Avengers: Infinity War (Marvel, HF)
Josh Brolin as Thanos in Avengers: Infinity War (Marvel)

Hear us out, and imagine this story: after empowering Heimdall and Wakanda’s Heart-shaped herbs in its journey through the cosmos, the Soul stone was gifted to Adam Warlock by his creators, only for Iron Man to get his hands on it in order to power a weapon that could take down Thanos.

In the course of battle this failed, and all present were transported to Soul World, perhaps until Hulk picked up the stone himself and tamed it to his will – or until Thanos took it for himself, gaining control of his Infinity Gauntlet and ending the first of this two-part Avengers story on one hell of a cliffhanger.

Yes, this would be ridiculous, contrived, kinda cheesy and inconsistent with much of what we’ve seen before in the Marvel Cinematic Universe – but to be honest, it’s probably not more far-fetched than what the eventual real answer will turn out to be.

Unless, of course, they go with the whole “stuck to the back of Cap’s shield idea” we pitched right at the start, and make the internet’s mad theorising look even more unhinged by comparison. After all the twists in The Last Jedi, we wouldn’t be entirely surprised….


Avengers: Infinity War will be released in UK cinemas on 27th April