Fans have suspected for some time that the undead will play a role in What If...?, and they were right. According to Marvel's Expanding the Universe special on Disney+, in one of the planned plots for the new show, Steve Rogers is going to be zombified and it will be up to his longtime friend and sometime enemy, Bucky Barnes (aka The Winter Soldier) to stop him spreading a zombie plague. From the information teased by Disney and Marvel, this story looks to be set in wartime, around the time of Captain America: The First Avenger.

In addition to starring in the Disney+ original The Falcon & The Winter Soldier , Sebastian Stan will also voice Bucky in this one-off story, which takes place outside the continuity of the Marvel Cinematic Universe.

Earlier this year, Marvel confirmed that one What If...? story would revolve around Peggy Carter , exploring what would happen if she had been injected with the super-serum instead of Steve Rogers. That episode will show the character, voiced by returning actress Hayley Atwell, taking on the mantle of Captain Carter, a Captain America-style figure but with a few distinctly British traits. (Another similar What If...? comic storyline from 1978 showed Jane Foster proving herself worthy of wielding Thor's mighty hammer a premise which was later revisited at length in the comics and provides the basis of the next movie, Thor: Love & Thunder .)

Each installment of What If...? will be introduced by The Watcher, a Rod Serling-type character played by Jeffrey Wright, who acts as the viewer's guide to all of the alternate timelines and realities explored in the show.