Endgame Writers Reveal What Happened With The Soul Stone

Of the six Infinity Stones, the Soul Stone is arguably the trickiest to wrap your head around. Of particular concern is the question of what happens to the stone if it's returned to the place from which it was taken. Thankfully, the writers of Avengers: Endgame have come forward to explain exactly what happened to the Soul Stone in the film.
First, a little refresher. Avengers: Endgame sees Black Widow and Hawkeye take a trip to the mysterious planet of Vormir on a mission to pluck the Soul Stone out of time before Thanos or his minions can acquire it. Hawkeye ultimately obtains the Stone after Black Widow heroically throws herself off the planet's massive cliff, echoing the same sequence from Infinity War in which Thanos killed Gamora for the stone.
Before he retires to a life of slow dancing with Peggy Carter at the end of the movie, Captain America travels back to the past to place the Stone in the same spot it was in before Black Widow sacrificed herself.
As MCU fans now know, there are pretty specific rules for what has to happen before someone can take the Soul Stone from Vormir.
After Infinity War and Endgame, we've seen that part of the process go down twice. But we've never before seen anyone try to put that Soul Stone back. How did Cap successfully return the Soul Stone? And, perhaps more importantly, would putting the Soul Stone back revive the person who died for it?
Christopher Markus and Stephen McFeely explained during a recent episode of CinemaBlend's HeroBlend podcast that Captain America faced no trouble returning the Soul Stone, but sadly, the soul-for-a-soul exchange that Black Widow and Hawkeye made with the keeper of the Stone, Red Skull, wasn't reversed in that moment.
Unfortunately, this shows that just because the Soul Stone was returned doesn't mean that those who were sacrificed to retrieve it get to come back to life. The exchange is permanent, and the soul that was sacrificed can't be retrieved.
As Markus put it,
"You put it back, but you don't get anything in return. It's not like a pawn shop."
While fans held onto the hope that Black Widow could perhaps be resurrected once Captain America put the Soul Stone back on Vormir, that's apparently not going to happen, as it's simply not the way the Soul Stone works. Cap returning the Soul Stone only patched up the timeline, it didn't undo Black Widow's death.
This has a huge repercussion on the future of the Marvel Cinematic Universe, since Marvel Studios is currently developing a Black Widow solo movie. How that's going to work with a dead Black Widow is sort of up in the air. It's possible the movie will be a prequel, giving us the backstory for Black Widow that the other MCU movies have only ever teased at. It's also possible that she really is alive out there somewhere, brought back by Hulk's use of the Infinity Stones without him or anyone else knowing about it. It's also possible that the movie will focus on an entirely different Black Widow; at this point, we just don't know.
While Marvel has kept quiet about the film, there have been some clues as to when Black Widow's solo adventure might be set. Past reports pin the film as being a period piece, set partially in Natasha Romanoff's younger years working with the KGB, and then jumping forward to 15 years after the fall of the KGB.
If Markus and McFeely are to be believed, and there truly is no way that Nat can be resurrected, then there isn't any other point in time that Black Widow screenwriter Jac Schaeffer can place the film other than years before the events of Avengers: Endgame.
Losing Black Widow in Avengers: Endgame was a painful experience. And though she may never come back to life in the present day to join the Avengers who lived through the film, it looks like super-spy is all set to make at least one more appearance on the big screen before fans say goodbye.