Everybody is excited for the release of 'Avengers: Age of Ultron,' which is going to be the culmination of everything that has been presented in the second phase of the Marvel Cinematic Universe. And as the date of the premiere approaches, more theories are beginning to emerge regarding the direction of franchise. One of these theories is that Tony Stark's modified arc reactor is actually an Infinity Stone.

An article published by Movie Pilot (reported via Cinema Blend) theorized that the element Tony Stark "re-discovered" in 'Iron Man 2' may be an Infinity Stone, as it was based on his father's research on the Tesseract. Fans of the MCU would remember how Howard Stark, Tony's father, got his hands on the Tesseract while he was looking for Steve Rogers after the defeat of Hydra. In the film 'Captain America: The First Avenger,' Steve gave Howard a sample of a core component of the Hydra weapons, which the former presumably began studying on after finding out about the power it possessed. Additionally, a drawing of the tesseract appeared in Howard's notes that Tony was reading while trying to find a replacement for the Palladium core in his arc reactor, which has led many fans to believe that the new element he replaced the Palladium with may be like the Tesseract itself.

The article also pointed to a scene in 'The Avengers' (where Loki fails to take control over Tony after touching his arc reactor with the scepter) as evidence that his arc reactor may be an Infinity Gem as Erik Selvig later in the movie explains that the Tesseract cannot fight or protect from itself. This may mean that an Infinity Stone cannot fight another one, which could then verify that the reason why Loki's scepter could not control Tony was because he was in possesssion of another Infinity Stone (many speculate that the orb on Loki's scepter is the Mind Gem).

So why is this significant?

If this theory is proven correct, then Tony may hold the key to defeating Thanos, who is believed to be the big baddie in the 'Avengers: Infinity War' storyline. In the comics, Thanos has been looking for the Infinity Stones to take control of the universe, but Tony and his team called the Illuminati find the gems first and distribute them to each other to protect them from being taken.

'Avengers: Age of Ultron' premieres in U.S. theaters on May 1, 2015, while the two-part 'Avengers: Infinity War' is slated for a 2018 and 2019 release.