"Avengers 4" has begun filming and The Russo Brothers shared this cryptic image of a glove on Facebook with the message, "Beginning the end."

So what does it mean? Whose glove is it? (It certainly doesn't look like Thanos's Infinity Gauntlet. Or any piece of Iron Man's outfit.) What does "the end" mean? *Gulp*

"Avengers 4," which doesn't yet have a subtitle, has been teased as a "game-changer" for the Marvel Cinematic Universe. It's the sequel to "Avengers: Infinity War," which wrapped just before Comic-Con.

Anthony Russo (who is co-directing with brother Joe) told EW last year, "These two movies are intended to be the culmination of everything that has happened in the MCU since the very first Iron Man movie. ... These movies are in some ways going to be an end to certain things, and in some ways, they're going to be the beginning of certain things."

Well, that's as clear as mud.

But does this mean the end for Captain America? Chris Evans told EW in June that "Infinity War" and "Avengers 4" will "wrap up everything" and that it will round out his six film contract with Marvel.

Explained Evans: "I had six films in my Marvel contract, so I could have said after the third Avengers I was done, but they wanted to make the third and fourth Avengers films as a two-parter. They said they had so many other characters to fit in — Guardians of the Galaxy, Black Panther, Captain Marvel, Doctor Strange, Ant Man -– and couldn't get them all into one movie ... It made sense."

Damn, we'll hate to see Cap go!

"Avengers: Infinity War" opens May 4, 2018, and "Avengers 4" is set for May 3, 2019.

For what it's worth, we haven't yet (to the best of our recollection) seen Cap wear gloves like those featured in the photo. He favored fingerless gloves in "Captain America: The Winter Soldier" and "Civil War" and long red gloves in "The Avengers."

[Via EW, Facebook]