Avengers: Endgame - Every Mystery The Russos Have Answered (So Far)

6. The Time Stone Mystery

The Question

Given that he had access to the Time Stone at the end of the movie, before Captain America took it back to the past, why didn't Doctor Strange use the Time Stone to reverse time and save Tony Stark?

We'd seen Thanos was able to turn back the clock on Vision's death and indeed on the injury in his own chest when Thor hit him with Stormbreaker. We'd also seen Doctor Strange focus the Stone on an apple and return it from eaten to uneaten, so it's not like the Stone would have to change everything around Stark too.

The Answer

This is one of those answers that isn't quite as satisfying as you'd like, because the Russos have contradicted it elsewhere, but the answer exists all the same. They say that Tony killing himself was crucial to defeating Thanos and undoing it just wasn't possible:

"It’s because even if you save Iron Man, it will still not change the fact that Thanos will eventually win the war. Among the 14 million possibilities that Doctor Strange has seen, Iron Man’s sacrifice is a must for that one win scenario."

But again, that's not right. The apple disproves it and the mouse being the one thing different in the 14 million alternate futures confuses this one. So maybe the apple wasn't canon and the mouse did it more than once?