7 Infinity Stone Theories That Marvel Fans Should Read Before 'Avengers: Infinity War'

After a decade of teasing fans with glimpses of the all-powerful Infinity Stones, Marvel is finally putting them center stage in Avengers: Infinity War. The new movie will center on the mad titan Thanos's quest to collect all six Infinity Stones and destroy the world. Although we've seen most of the stones before in Marvel movies, much about them is still a mystery to fans. Read up on these Infinity Stone theories before seeing Avengers: Infinity War to get a better understanding on what's really going on.

First, a little backstory. Even though some movie fans may not have been aware of it, the Infinity Stones have made appearances in almost every movie in the Marvel Cinematic Universe. The Space Stone was first to appear, within a cube called the Tesseract, and then there was the Mind Stone in Loki's scepter, the Reality Stone in the form of liquid Aether, the Power Stone encased within an orb, and the Time Stone inside the Eye of Agamatto. The only stone we have yet to see is the Soul Stone, which will finally be revealed in Avengers: Infinity War.

Although nothing about the Soul Stone has been officially confirmed, a ton of fans have theories about where the final piece to the puzzle might pop up. Have we already seen it before? Is it in a whole new setting? Here are all the best theories about the missing Infinity Stone right now:

1. Wakanda Has The Answers

Since it was the final standalone Marvel movie before Avengers: Infinity War, many fans were assuming Black Panther would reveal the Soul Stone, but that did not explicitly happen. Still, some fans think the Soul Stone subtly appeared in Wakanda. Popular theories point to the orange sand that T'Challa sinks into to enter the ancestral plane (the Soul Stone is orange and speaking to spirits definitely fits its M.O.), or the heart-shaped herb that grants him his power. A broader theory claims that the Soul Stone was in the meteor that struck Wakanda eons ago and granted the land with its magical properties.

2. Look For The "H"

One theory that has been around for a while now is that the vessels carrying each Infinity Stone also carry a hidden importance. Fans have notices that the first letter of each vessel seems to be spelling out the name Thanos, and the only letter is the "H." That would suggest that the Soul Stone is being held in something that begins with the letter "H." This helps the odds of the heart-shaped herb in Wakanda, and also leads into another popular fan theory...

3. It's Heimdall's Time To Shine

All the way back in the first Thor movie, hardcore Marvel fans began to suspect that an orange gem on the chestplate of Heimdall's armor may actually be the Soul Stone, and now that theory has grown more and more believable. Not only would Asgard's all-seeing gatekeeper fit into the "H" theory, but his glowing orange eyes and inexplicable power to see and speak with people across the galaxy seem to jibe with the Soul Stone's abilities.

4. The Secret To Iron Man's Strength

Another popular theory is that Infinity War could reveal a major twist centered on one of the MCU's central characters. Some fans think that Tony Stark actually has the Soul Stone within him. Subscribers to this theory point to Tony's dad calling his son "his greatest creation" in Iron Man 2, and the fact that Howard Stark was so devoted to his lab work that it didn't totally make sense for him to suddenly try to have a child later in his life. The theory claims that Howard found the Soul Stone and accidentally created a human life — Tony's — while experimenting on it.

5. A Trip To Titan

Fans claim that the Avengers: Infinity War trailer briefly shows Doctor Strange on Thanos's home world of Titan. All we really know about Titan is that it was left desolate after a mysterious apocalyptic event. Obviously, something powerful enough to destroy a plant points to Infinity Stones, so the Soul Stone may very well still be chilling on Titan.

6. The Avengers' Newest Addition

Since Black Panther didn't deliver the Soul Stone, all eyes are on the final newcomer to join the team in Avengers: Infinity War. Since Brie Larson's upcoming Captain Marvel origin story movie will be set in the 1990s, Carol Danvers will have definitely gotten the hang of her powers when she drops into Infinity War. She will also be the only major character we don't really know anything about... maybe she will even reveal some connection to the Soul Stone.

7. Thanos Already Has It

All of these theories about where the last Infinity Stone could be assume that Thanos doesn't already have the missing stone. There is a definite possibility that the mad titan has the Soul Stone in his possession when the movie begins.

We will just have to wait and see which of these theories (if any) proves to be true when Avengers: Infinity War lands in theaters on April 27.