The excitement for the upcoming Marvel movie, "Avengers: Infinity War" is undeniably building up and the fans were delighted to discover that Gwyneth Paltrow is going to be part of the movie. Before proceeding to read the rest of the article, please be informed that it may contain potential spoilers for the upcoming Marvel movie.

To continue, fans of the "Iron Man" franchise have been speculating that there's a looming twist related to Tony Stark.

In "Captain America: Civil War," Tony Stark had a falling out with his fellow superheroes. Followers of the franchise are expecting the falling out to worsen in "Avengers: Infinity War", especially since Thanos, will be entering the picture.

The possible "Iron Man" twist in "Avengers: Infinity War" might have something to do with Tony Stark having a total change of heart when it comes to his superhero lifestyle. The existence of Thanos in the next Marvel movie is expected to be a major game-changer.

The return of Gwyneth Paltrow

In previous "Iron Man" movies, the only person that could pacify and talk logic to a furious Tony Stark is Pepper Potts, played by Gwyneth Paltrow.

According to Comic Book, Robert Downey Jr. recently posted a photo of him with Gwyneth Paltrow and Favreau which seems to be on the set of "Avengers: Infinity War."

Eagley-eyed netizens noticed the costume that Robert Downey Jr. was wearing - which featured a jacket tied around his neck that worked as a scarf. Speculations surfaced that the jacket tied around his neck was not for fashion purposes only, but instead, it looked like it was used to cover up a certain type of arc reactor.

What does the new arc reactor mean?

According to Comic Book, the new arc reactor appears to be something that Tony Stark has never used or encountered before. Further, it seems to be much bigger than his usual arc reactors which explain the slightly obvious cut-out on Downey's costume in the photo.

The fans have been keen on Tony Stark's ark for "Avengers: Infinity War" because of earlier this year, Marvel already teased the fans with a photo that showed Downey hanging out with fellow actors on the set wearing a costume with a big hole in the chest area. Understandably, it led to speculations that Tony Stark might have a different arc reactor in the next Marvel movie. It's still unclear what the new arc reactor is for, but the majority of the fans are betting that it's in preparation for Thanos. "Avengers: Infinity War" is scheduled to premiere on the big screen on May 4, 2018.