For approximately seven decades, Sebastian Stan's Bucky Barnes has relied on a cybernetic arm to carry out his missions as the Winter Solider. However, towards the end of Captain America: Civil War, Bucky's prothesis was torn off by Iron Man during their fight in Siberia. Fortunately, Bucky won't be without an appendage replacement for long, as he briefly seen rocking a new metal arm in the Avengers: Infinity War trailer. More importantly, it sounds like this arm will be even better than its predecessor due to how it's possibly been constructed from Wakandan technology. As Infinity War co-director Anthony Russo explained:
For everyone who's seen Captain America: Civil War, they know Bucky was taken in by T'Challa in Wakanda. I think that, you know, we catch back up with him after he's been there for a while, and if there's an influence on his arm, it may perhaps have to do with that country that he's been spending time in.
In case you need a refresher on Captain America: Civil War's final moments, Bucky Barnes and Steve Rogers were granted asylum within Wakanda, and fearing that the lingering HYDRA programming in his head would case him to hurt more people, Bucky decided to go back into deep freeze until the Wakandan scientists could find a cure for his brainwashing. Evidently they succeeded, as Bucky will be joining Steve, their Avengers allies and Wakanda's warriors in battling Thanos' monstrous forces during Avengers: Infinity War. But additionally, as Anthony Russo implied to We Got This Covered, it would seem that Wakanda's brightest minds have put their resources to good use on Bucky's new arm, and while it remains to be seen what exactly these enhancements are, I imagine that the main difference will be that the new arm is constructed out of vibranium.
Along with being the most technologically advance nation on Earth, Wakanda also benefits from its large supply of vibranium, the rare metal that can absorb sound waves. It's the same metal that Captain America's shield is made out of, and since adamantium rests firmly in the X-Men cinematic universe (although that may change once the mutant property is brought into the MCU following Disney's acquisition of 20th Century Fox), it's also the only metal in the MCU that we know of which is nearly indestructible. If Bucky's new arm is made out of vibranium, it's guaranteed he'll pack an even more powerful punch. But we also shouldn't count out this new appendage potentially being packed with other useful features and gizmos, similar to Phil Coulson's hand in Agents of S.H.I.E.L.D.
For those interested in re-watching the quick glimpse of Bucky Barnes rushing into battle, give the Avengers: Infinity War trailer another look below.
You can see the Winter Soldier back in action when Avengers: Infinity War opens in theaters on May 4, 2018. To learn what other movies are coming out over the next 12 months, check out our 2018 premiere guide.