One of the great quests of the Marvel Cinematic Universe, going all the way back to the early days of Phase 1, remains assembling all six of the Infinity Stones. Now that Doctor Strange is out, we know that there is only one remaining Infinity Stone to be found. Or is there? A new, and pretty solid, fan theory suggests it has been right in front of our eyes the whole time.

The theory comes from a guy named Ryne Short, who submitted it to He posits that Heimdall, played by Idris Elba in the Thor movies, has the Soul Stone, safely on Asgard. Here is how Ryne Short backs up his theory.

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"In Norse mythology, Odin gives him his sight. Heimdall's eyes are orange. In Thor: The Dark World, he is quoted saying he can see all the souls in the nine realms. And in Thor's vision in Age of Ultron, Heimdal is blind. Thanos could have taken the stone from his eyes. It all fits."

The Soul Stone has only been seen in Guardians of the Galaxy when The Collector was explaining what they were. If you look at the Soul Stone in that sequence, it pretty much matches the color of Heimdall's eyes perfectly. That, coupled with the other evidence that Ryne Short has presented makes this theory seem very compelling.

The other Infinity Stones are scattered about the MCU. The Space Stone, otherwise known as the Tesseract (first seen in Captain America: The First Avenger), is currently on Asgard. The Reality Stone, or the Aether from Thor: The Dark World, was in The Collector's collection for safe keeping, but since his collection was blown up, it could be somewhere else. The Power Stone, first seen in Guardians of the Galaxy, is safe with the Nova Corps. The Mind Stone, which was originally Loki's scepter from The Avengers, is now firmly planted in Vision's head. Lastly, the Time Stone, aka the Eye of Agamoto, was seen in Doctor Strange and is currently safe at the Kamar Taj.

So how plausible is this theory? There are a couple of issues. For one, Thanos is going to need to collect all of the Infinity Stones at one point. That being the case, he is going to have to take the Mind Stone from Vision, which will require Thanos ripping it from his head. Assuming Heimdall does have the Soul Stone, it would be some version of the same thing. It would maybe take away some of the weight and gravitas of what will probably kill Vision. Probably. Also, Thor took an Infinity Stone to The Collector because he didn't want two Infinity Stones in the same place. If Heimdall does have the Soul Stone, there are two Infinity Stones on Asgard. That doesn't mean this theory isn't true, these are just the best arguments against it. Either way, this is easily the best theory anyone has come up with about the Soul Stone. If it turns out to be true, we will probably get confirmation in Ragnarok next year.

For now, we will have to see what Marvel Studios still has coming down the pipe for Phase 3, which is a lot. James Gunn's Guardians of the Galaxy Vol. 2 is due out on May 5, 2017. That will be followed closely by Spider-Man: Homecoming on July 7, 2017, with Thor: Ragnarok poised to bring some long awaited Planet Hulk action (and maybe an Infinity Stone) on November 3, 2017. 2018 will see the release of Black Panther on February 16, Avengers: Infinity War on May 4 and Ant-Man and the Wasp on July 6. Finally, 2019 will bring us the arrival of Brie Larson as Captain Marvel on March 8 and the conclusion of Phase 3 with Avengers 4 on May 5.