New Captain America 4 Footage Confirms Big X-Men-Related Theory, New Villains

Marvel Studios opened its San Diego Comic-Con panel on Saturday night with some footage of "Captain America: Brave New World." The panel also wound up confirming some rumored details about the movie that weren't completely apparent from the film's first trailer.

Part of the presentation included a clip where President Thaddeus "Thunderbolt" Ross (Harrison Ford) discusses the remains of the late Celestial Tiamut, whose "emergence" was thwarted (and humanity saved) back in 2021's "Eternals." A rumor circulating recently has claimed that the remains of Tiamut will be the source of adamantium (the metal alloy that Wolverine's skeleton and claws are coated in). This has seemingly been confirmed; in the footage shown tonight, Ford's Ross declares that "adamantium belongs to everyone."

Not only that, but the identity of Giancarlo Esposito's mystery villain has finally been confirmed: He's playing Sidewinder, King of the Serpent Society. These villainous snakes were previously confirmed to be in the movie (Rosa Salazar is playing Rachel Leighton/Diamondback, supervillain and sometimes girlfriend of Captain America), and it looks like their presence survived the substantial reshoots "Brave New World" underwent.

But what do these reveals suggest about the story of "Brave New World"?

The Serpent Society seem likely to be first act villains — characters who can kick off the movie with a big set piece where Sam Wilson (Anthony Mackie) proves to the audience he's a worthy Captain America by kicking their scaly behinds.

But this suggested origin of adamantium (tying it to the Celestials) is a big difference from the comics; there, it's a man-made alloy like steel. However, the metal has been absent from the MCU so far (it's mostly associated with the X-Men, after all). The movies have generally substituted adamantium with vibranium, the other super-strong metal of the Marvel Universe. That replacement could factor into how the story plays out.

"Black Panther: Wakanda Forever" suggested that the nations of the world, especially America, aren't fans of how Wakanda's monopoly on vibranium makes them the most powerful country on Earth. CIA Director Valentina Allegra de Fontaine (Julia Louis-Dreyfus) even appeared pretty gung-ho about invading Wakanda.

Adamantium could well be depicted as the American empire's manna from heaven, a resource that can allow them to compete with or even outpace Wakanda and its vibranium technology. The remains of Tiamut are still in the Indian Ocean, which likely complicates matters for the U.S. getting its hands on that giant adamantium husk. A "Captain America" movie that actually deals with some significant international politics ought to be extremely interesting. 

"Captain America: Brave New World" opens in theaters on February 14, 2025.