Sebastian Stan knows nothing about Avengers: Infinity Wars — except what he's already filmed, of course. But beyond that, he knows nothing. Or he says.

According to Stan, he only knows what the filmmakers want him to know. In fact, he doesn't even get a script until the day of filming. But when you consider the stakes of Avengers: Infinity War, and what directors Joe and Anthony Russo have set out to accomplish with this two-part superhero spectacle, all that secrecy starts to make sense. Production is currently underway on the untitled Phase 3 finale, Avengers 4.

"It certainly is the biggest culmination of anything and everything they've done so far," Stan told MTV News correspondent Josh Horowitz at the Toronto Film Festival, where the actor is currently promoting festival favorite I, Tonya. "It's just going to be bigger and crazier than anything."

Because of the sheer magnitude of the events of Infinity War and Avengers 4, Stan at times feels like he's in an episode of Game of Thrones — which may or may not bode well for Bucky Barnes. "I feel a lot like that Jon Snow character [in] 'Battle of the Bastards,'" Stan said. "When there's that shot of Jon Snow, from the back as horses are charging at him and he's just standing there, that's kind of how I feel on set at times. Will I make this stampede or not?"

Well, that's a harrowing image. (Here's hoping Cap saves the day with the Vale.)

While Stan wouldn't divulge too many details about Bucky's role in Infinity War — although, lucky fans who attended either D23 or San Diego Comic-Con this past summer know that the Winter Soldier is out of the cryogenic chamber and fighting alongside Black Panther in Wakanda — he did add that Bucky, as per usual, is still "figuring out where he's at."

As for those rumors that Bucky will take up the Captain America mantle following Chris Evan's forthcoming retirement from the Marvel Cinematic Universe, "it's just speculation." (You know nothing, Stan.)

First, Stan said, "we've just got to all survive this war." If Stan is already comparing Infinity War to Game of Thrones, we've never been more certain of a major impeding MCU death.