Despite the imminent release of Avengers: Infinity War, fans are already trying to figure out what to expect when its untitled sequel premieres in theaters next year.

Because both movies were filmed back to back to accommodate the massive cast of Marvel Studios actors, we've already seen glimpses at the set of Avengers 4 that have some fans guessing that time travel will be involved. But co-director Joe Russo revealed to Empire Magazine that the fans would look at one of their previous films for the answer.

"You should go back and look at clues in [Captain America:] Civil War to what's in that movie," Joe said.

The set photos in question show Chris Evans as Captain America, all clean shaven, on a destroyed street in New York City. He's wearing his classic costume seen in The Avengers, though he appears to be interacting with Ant-Man, who was not present for the Battle of New York.

And though some fans have theorized that some Time Stone shenanigans could be taking place, another photo revealed the existence of a carrying case that had the word "BARF" written on it.

That actually has a different meaning in the Marvel Cinematic Universe than the bodily function, referring to a piece of Stark technology that debuted in Captain America: Civil War.

B.A.R.F. stands for Binarily Augmented Retro-Framing allowed Tony Stark to "hijack the hippocampus" and help him work through his memories of his parents before their deaths. It seems like reliving the Battle of New York will play into the new film, but not in the way people are expecting.

While speaking about Avengers 4, co-director Anthony Russo called it "the Question Mark film," and said it would be different from the Infinity War heist-inspired plot.

"It's more of an epic adventure in the classic sense, with huge emotional stakes," said Anthony.

Writer Stephen McFeely, who worked on both films with partner Christopher Markus, stressed that both movies will have a different feel and that fans will be surprised when they learn more about the untitled sequel.

"Nobody knows, and that’s what makes me particularly excited. I look all the time on the internet: people have no idea!" said McFeely. "[Avengers] 4 resolves the intrigue of Infinity War; [the movies are] clearly linked, but they almost seem to belong to two different genres. We did not want to cut a film in half and say, 'Pay now and come back in a year for the rest!' These are two very different stories, on a tonal and structural level."

Hopefully we learn more when Avengers: Infinity War premieres in theaters on April 27th.