Avengers: Doomsday is the forthcoming superhero film and the 39th entry in the Marvel Cinematic Universe (MCU). It will be a direct sequel to 2019's Endgame and the fifth in the Avengers series. Anthony and Joe Russo are returning to the director's chair. The film will be released by Walt Disney Studios Motion Pictures on December 18, 2026.A year before its release, the film's trailer was reportedly leaked on the internet. It possibly showcases the return of Steve Rogers, aka Captain America. So let's take a look at all the available details.Avengers: Doomsday - First trailer leaked onlineAvengers: Doomsday's first trailer is reportedly attached to the prints of Avatar: Fire and Ash. It's seemingly part of Marvel's plans to drop teasers of their forthcoming films on a week-by-week basis. But before that, the first teaser has reportedly already leaked online.As per people who have seen the video, it marks a return of Steve Rogers, aka Captain America. We get to see Chris Evans returning as the righteous superhero. If this is true, it is expected to shock fans as Evans has said that he was done with the franchise.Social media influencer Matt Ramos took to X (formerly Twitter) to share his reaction to the reportedly leaked trailer. The clip features a person reaching a spot on a motorbike. He is eventually revealed to be Steve Rogers, who then goes inside a house where he lived with Peggy Carter. He then leans on to pick up his superhero uniform, but changes his mind and picks up his infant son.The scene then fades to black, and the text reads, "Steve Rogers will return in AVENGERS: DOOMSDAY". This is followed by the logo of the Avengers and a release date countdown.Avengers: Doomsday is written by Stephen McFeely and Michael Waldron, while the Russo brothers have produced it with Kevin Feige. The film focuses on several superhero teams coming together to stop Doctor Doom (played by Robert Downey Jr.). Robert had played Iron Man in the previous phase of the MCU.Other cast members include,Chris Hemsworth as ThorVanessa Kirby as Sue Storm, aka Invisible WomanAnthony Mackie as Sam Wilson, aka Captain AmericaSebastian Stan as Bucky Barnes, aka Winter SoldierLetitia Wright as ShuriPaul Rudd as Scott Lang, aka Ant-ManWyatt Russell as John WalkerTenoch Huerta Mejía as NamorEbon Moss-Bachrach as Ben Grimmaka The ThingSimu Liu as Xu Shang-ChiThe film will release on December 18, 2026.Stay tuned to Soap Central for more such stories.