That's because Captain America: Brave New World brings adamantium into the fold. The substance shows up in the body of the Celestial that emerged from the Indian Ocean in Eternals. Now, it's the cause of international conflict, as major world powers try to control the world's only known adamantium supply.

Brave New World brings back one of the Marvel Cinematic Universe’s most underutilized villains after a 16-year absence. Samuel Sterns (Tim Blake Nelson) was last seen in 2008’s The Incredible Hulk when exposure to Bruce Banner’s blood triggered his transformation.

Harrison Ford as Thaddeus Ross is a game changer for Marvel's newest movie, but the end of Captain America: Brave New World left us with a burning question.