Avengers 4: 10 Things Fans Demand

7. Captain America Fights The Red Skull On Vormir

Though it's entirely possible that the Red Skull's last appearance came in Infinity War, it's likely that fans are banking on the character to link up with Steve Rogers at some point.

Theories have abounded in the weeks following Infinity War's release regarding the fate of all the souls lost to Thanos' snap, and with the Skull having increased in power on an exponential scale since his war days, it wouldn't be disingenuous to assume that the character could feature significantly in Avengers 4's story.

His purpose as the Stonekeeper was pretty obvious, but without that responsibility, could the Skull now be free to do as he pleases? Or is he now responsible for the lives that could, ostensibly, be trapped in the soul realm?

No one knows, but if any of these theories come true then it's likely that Rogers will come face to face with the man he fought against during the Second World War. That's a really fascinating (albeit twisted) reunion, and in closing the door on both the Skull and Captain America's respective journeys, it's an opportunity Marvel can't afford to pass on.