There's a new Captain America film in the works, with Anthony Mackie (as Sam Wilson) and not Chris Evans (as Steve Rogers) in that titular role. And while Evans' time as Captain America may be over, his time in the MCU may not be.
You only have to look at the comics and a little Easter egg in Disney Plus' The Falcon and Winter Soldier to see what Marvel Studios could be up to.
The Falcon and the Winter Soldier Easter egg
In the first episode of The Falcon and the Winter Soldier, Sam Wilson's Air Force liaison Joaquin Torres (played by Danny Ramirez) asks about the whereabouts of Captain America.
Remember, the general public in the MCU didn't see the elderly Rogers/Evan return at the end of Avengers: Endgame and pass the shield to Wilson. The only thing we can suss out is that publicly, it's believed that Rogers is gone – perhaps dead – given the memorials in this show and the musical seen in the Hawkeye series' trailer.
In quizzing Rogers' former partner Wilson about his status, however, Ramirez mentions there are "crazy conspiracy theories" online, including one specific one Marvel Studios made it a point to be included: "They think that he's in a secret base on the moon looking down over us."
Wilson blows that off… but there's something to it. In Marvel Comics, there is an aged former hero with a secret base on the moon looking down over us. It's actually a mantle, like the Captain America name, but called 'The Man on the Wall.'
Marvel Comics' Man on the Wall
The Man on the Wall is the name for the person (or persons) that acts as Earth's secret first line of defense against space invaders. Although its origin isn't completely known, it's intertwined with the secret origin of SHIELD that goes back to ancient Egyptian times.
Of the four people comics readers know as the Man on the Wall, each one generally makes the role their own – especially in the choice of tactics, methodology, and bloodshed. For some, it's a swashbuckling Flash Gordon type of adventure, while for others it's a 'big picture' methodical toppling of alien civilizations and governments by an unseen hand.
The earliest known Man on the Wall in Marvel Comics is Eben Stafford, an early 20th-century warrior who actually led a team called the Men on the Wall. Although stories about his time are limited, he is known to have helped fend off a Martian invasion of London in 1917. After his team was killed off by intergalactic slavers known as the Entari, Stafford became more proactive about alien threats against Earth - and where he could, striking first out in space before they even made it into orbit.
Stafford abruptly vacated the role years later after finding someone who would be his replacement - Woody McCord, whose family was taken by those same Entari slavers.
McCord's time as Man of the Wall hasn't been written about much, except for his last mission – teaming with Howard Stark (Tony Stark's father) in 1958 to fend off an invasion by aliens known as Tribellions. It's during this mission that he meets then-CIA agent Nick Fury, and after a fatal injury warns Stark and Fury about the threats he's been fighting against.
It's here that Nick Fury picks up the mantle of the Man on the Wall, years before he would even take a role with SHIELD.
As revealed in the 2014 Marvel comics event Original Sin, Nick Fury secretly acted as the Man on the Wall for his entire tenure with SHIELD – but kept it a secret, even more so than the secrets he kept as Marvel's preeminent spy.
It all fell apart when he realized the Watcher's memories – featuring pretty much everything to ever happen on Earth in Marvel Comics – was saved in his eyeballs, so Fury killed the Watcher and stole an eye in order to find these criminals.
That action set about a chain of events where the Avengers eventually discovered what Fury had done, and Fury finally reveals his biggest secret – the Infinity Formula that had kept him young since World War II had faltered and he now looked close to his age as a nearly 100-year old man. For a time he used LMDs (Life Model Decoys) looking like his younger self to keep the mirage going, but after his murder of the Watcher was discovered, he realized his time was running out.
After Fury's apparent death at the hands of the villain Midas (who was also after the Watcher's eyes), Bucky Barnes (AKA the Winter Soldier) picked up the slack and took over as the Man on the Wall.
The Winter Soldier's time as the Man on the Wall is the most written about in comics so far, but also the most uneven. After a pair of off-world adventures in the 2014-2015 series Bucky Barnes: The Winter Soldier, Barnes' work defending against aliens has largely been absent from Marvel comics except for a brief time being the bodyguard for the living Cosmic Cube, Kubik.
What this could mean for Chris Evans/Steve Rogers in the MCU
While Captain America/Steve Rogers has never been the Man on the Wall in comics, the position Marvel Studios has left Chris Evans' role in at the end of Avengers: Endgame could lend itself to the role. Of note, there's also a series based on Secret Invasion setting the stage for what could be a surprise third act for the MCU Sentinel of Liberty.
In comics, there was a time where Steve Rogers' Super Soldier Serum stopped working, leading to him showing his age – nearly 100-years old. This is very similar to Nick Fury's final years as comics' Man on the Wall. In comics, an aged Steve Rogers passed the Captain America mantle on but remained involved in a 'big picture' way – in some ways filling the informal role Fury in relation to Marvel's heroes.
It's possible that MCU Steve Rogers eventually falls into this: he has the resources thanks to not only the adventures we know about, but the untold stories of him traveling through time setting the Infinity Stones back in their place.
Also, unless there's a surprise we don't know about, the love of his life Peggy Carter is indeed dead in both the main MCU universe well as the alt-reality he traveled to where he married her. With that part of his life over, he returned to the main MCU and bequeathed his shield and Captain America name to Sam Wilson.
Remember what Ramirez said in The Falcon and the Winter Soldier: "They think that he's in a secret base on the moon looking down over us."
Captain America was only part of Steve Rogers' life. Even as an elderly man in the MCU, if he sees a situation he can help in, why wouldn't he? What made him Captain America didn't leave with the name, and he knows more than almost anyone the threat of alien invasion.
Confused by the time jumps and alternate realities of the Marvel Cinematic Universe? Get your bearers with our MCU Timeline, laying out all the MCU movies and shows in chronological order.