In comic book movies, dead characters are only dead until they’re needed again. Marvel Studios is no stranger to cinematic resurrections, and now an actor has revealed that a character from the Captain America franchise will make a surprising return to the Marvel Cinematic Universe in next year’s Avengers 4. Does this appearance confirm a long-standing theory about what might happen in the superhero sequel?

So which Captain America character are we talking about here? Will Red Skull come back again? How about Arnim Zola, the scientist who “died” but uploaded his consciousness into a computer? Nope. (Well, at least not that we know of.)

Warning: spoilers for Avengers 4 ahead.

On the UFC Unfiltered podcast (via Heroic Hollywood), actor Frank Grillo revealed that his villain character Crossbones will be showing up in Avengers 4:

“[Crossbones] makes an appearance in the next Avengers movie, but it’s a flashback. And I’m allowed to say whatever I want because I’m never doing another Marvel movie…because I’m 117 years old.”

Avengers 4 Crossbones Appearance

For those who may not recall, Grillo played Brock Rumlow, AKA Crossbones, in Captain America: Winter Soldier and Captain America: Civil War. Crossbones poses as a S.H.I.E.L.D. operative but is actually a double agent working for HYDRA. His body gets burned at the end of Winter Soldier, which causes him to wear a bone-colored mask. In the beginning of Civil War, Crossbones tries to kill himself (and Steve) by detonating an explosive, but Scarlet Witch contains it – until she can’t hold it any longer and the explosion kills Crossbones and destroys a nearby building, setting the main plot in motion.

Grillo seemed pretty casual about revealing that Crossbones’ role in Avengers 4 takes place during a flashback. So either he’s telling the truth, or he’s potentially concealing something that fans have suspected for a long time: that this movie features time travel. We’ve seen set photos of various characters in previous versions of their costumes (specifically Captain America), and considering how the idea of time factored into Infinity War, it makes sense that at least one character might take a whirlwind journey back through the history of the MCU in an attempt to undo Thanos’ devastating snap.

To me, Crossbones is like the Boba Fett of the MCU: he has a cool character design, but he’s kind of a nothing character. I understand that he’s much more of a significant villain for Cap in the comics, but the movies never really gave him the proper breathing room to establish him as a truly worthy opponent. Will his appearance in Avengers 4 retroactively make him a more worthy foe? We’ll find out on May 3, 2019.