At this point it’s a foregone conclusion Avengers 4 will feature time travel as a pivotal plot point. We’ve seen spy shots from the set of the heroes wearing retro costumes and it still remains the only feasible way to undo the ‘Snappening’ aside from introducing a multiverse theory. For the sake of argument, if we can agree time travel will play a part, a new theory from Reddit suggests it won’t be the first time the MCU has used it. User Spilgles postulates Nick Fury’s cameo in Avengers: Age of Ultron was actually a future version of himself. He goes on to explain:

“I rewatched Avengers: Age of Ultron recently, and came across an odd bit of dialogue that really stuck out in light of events in Avengers: Infinity War and rumors about Avengers 4. When Nick Fury drops in on The Avengers at the farm, he does two things: he tries to talk Tony Stark into dropping his efforts into making super robots, and he gives the whole team a pep talk and starts the conversation that eventually leads to the creation of Vision.

With the hint / common theory that time travel is somehow involved in Avengers 4, it got me thinking: what if this was a future or past version of Nick Fury, dropping in on a crucial point to interfere with history, or to shepherd events in a particular direction?

A few things to consider:

When Fury surprises Tony in the barn, it’s Tony who says, “Who told you we were here, Maria Hill, right?” … and Fury changes the subject.

Then, Fury starts to try to talk Tony out of working on Artificial Intelligence. I think this is a big deal, because he must be aware that the quickest way to motivate Tony Stark is to tell him he can’t do something. Fury starts the conversation about AI, but it’s Tony who changes the subject to his fears about the future.

Later, Fury gives the team details about Ultron. This makes sense for both present Nick and (potentially time-traveler) Nick.

But, he says: “Back in the day, I had eyes everywhere. Ears, everywhere else. You kids had all the tech you could dream up. Now, here we all are, back on Earth, with nothing but our wit, and our will to save the world.” This struck me as odd, because when have we ever seen Nick Fury not on Earth? And who is the “we” that he means?

Also, it’s this conversation that sparks the brainstorming that ends up with Vision — and watching how Nick Fury guides the discussion, it begs the question: is he steering them to create Vision, and think that it was their idea?

My theory: This is not the Nick Fury they know from their present. This is a time-traveling Nick Fury who is there to make sure Vision is created with the infinity stone. This version of Nick Fury has been to space with The Avengers, which at the time of Age of Ultron, hasn’t happened yet for them.”