MovieChat Forums > Avengers: Endgame (2019) Discussion > *SPOILER*** the time travel issue

*SPOILER*** the time travel issue

So my understanding is that the way time travel works in this film is based on multiverses. So essentially, when they travel, they’re not going back in time in their reality, rather they’re travelling to a different reality. All their actions in that reality simply affects that reality while the one they travel from remains the same. This is the reason given for why the snap couldn’t be prevented by time travel (i.e. preventing the snap in another reality does not change their own) and also the reason why the ancient one is so protective of her own reality.

I think this was a great approach to time travel that was completely undone by cap’s ending.

So he travels in time to return the stones to their realities and chooses not to come back. This is fine and I’ll assume in that reality, the Steve Rogers there is still frozen in ice so there technically wouldn’t be two Rogers running around. But the problem is that back in the reality he comes from, Steve is still present and has become an old man. This is impossible based on the film’s own time travel rule. Steve travelled to a different reality and found his life there. This does not affect the reality he comes from. In the reality he comes from, he is simply gone. The realities do not intersect.


Yes, I also didn't exactly understand this.


Here is what I thought

They went back in time in their reality, but taking the stones would cause an alternate reality/timestream/universe to be created - as the Ancient one explained to Banner. Banner then said that if they took the stones, used them to bring the snapped people back, and then returned the stones to the exact moment they were taken, then they would avoid messing with things/creating alrernate timelines.

BUT even if Cap was able to return the stones perfectly, they seriously still messed up a lot.

NY 2012: Loki escaped with the Tesseract, the whole Strike Team thinks Cap is Hydra, PresentCap tells 2012Cap that Bucky is alive.

Morag 2014: knocking out Quill - what if he didn't wake up in time to get the stone before Ronan's guys showed up? Not that it really matters because freaking Thanos shows up and blows that entire timeline to hell. Nothing can fix that.

Asguard: I just think it's funny picturing Cap trying to sneak around trying to re-inject the Ether into Jane, and return the hammer.

Vormir: how exactly did he return the Soul stone? And how surprised was he when he saw Red Skull?

Even if Cap was able to return the stones perfectly, he still did one thing to completely mess with the timestream: He stayed in the past and married Peggy.


So PresentCap goes back to the past (time is unspecified - did he go to the 70s where he returns the Tesseract or did he go back to the 40s?). In that timeline he is still on ice. He and Peggy marry (do they have kids?) and they live a long happy life together until Peggy develops Altzheimer's and eventually dies. Nothing about her death was going to change. Does he stay relatively hidden/out of the public eye the entire time? That would ruin the legend of Captain America, and be pretty weird when he gets found in 2012. Let's presume the timeline has stayed intact.

Once the timeline reaches the Battle of NY in 2012, everything goes to hell. Loki escapes with the Tesseract therefore he's not in Asguard prison (unless by some miracle he is captured) when the Dark Elves show up. He's not there to give Kurse the directions out of the dungeon, so does Freya not die? Does Loki go to 2012Thanos and hand over the Tesseract? Does Loki just lay low?

The Strike Team now believes Cap is Hydra. 2012Cap now knows Bucky is alive. That messes with a lot in the 2 years between Avengers (2012) and Winter Soldier (2014) .

And then 2014Thanos and crew get yanked out of their timeline completely. That changes the events of Guardians, because it never ends up happening at all.

Ugh. I know that this is knit-picking to the nth degree. I really did enjoy the movie, but when you bring in time travel, it just gets messy.


I think you guys raise valid points. But as Banner explained, you go into the past, what you do affects that past’s future but your present remains the same. In other words, you create an alternate reality and you set the trajectory of that reality towards something different from your present but your present remains the same because the alternate past does not affect this reality.
This is why they couldn’t simply prevent the snap in the past because preventing the snap in an alternate reality will not change their reality. In their reality, everything remains the same. I.e. alternate universes as oppose to back to the future rules.

But that creates the problem I outlined regarding old man cap. If he lived in an alternate reality with Peggy, then he simply could not have grown old in this reality. He would exist up to the point of endgame and then simply ceases to exist at the point he travels in time.

I spoke to my wife and she theorised that one way around the loophole is that old man cap grew old in the alternate reality and used the pym particle to travel back into his own reality as an old man after Peggy died to pass the shield on to Sam.


So PresentCap goes back to the past (time is unspecified - did he go to the 70s where he returns the Tesseract or did he go back to the 40s?)

He probably jumped twice, first to 70s to return the tesseract, and then to 40s to meet Peggy, the old car that passes through before the dance scene looks like a 40s car.



They retrieved the Tesseract from the 70s after trying in 2012 failed. They never went to the 40s.


Seeing as how their actions are already going to cause changes to these alternate realities, why even bother with heisting the stones. For instance, Cap and Iron Man could have just popped into Avengers tower, prove that they are their future selves, and told themselves that they need to borrow the stones for about half a second. Same with Asgard.

That is literally what Hulk did.


True that. And while they’re at it simply tell them “yo, big purple guy sitting in the chair is about to get off his chair in a few years to collect these shiny rocks. You might want to look into that”


I think it's the studio decision, to give some kind of happy ending to Rogers.

Of course it's the multiverse kind of time travel. The moment they step foot on the past they already make a new timeline, this is the rule that is set by the writers and the one that Stark, Banner, and Nebula explains.

It can't be a single timeline because of what others have pointed out, and for an extra, present Nebula kills old Nebula. In a single timeline universe like Looper, it would have erased the present Nebula.


Exactly this.

The movie has plot holes but it’s always the case with time travel. It doesn’t bother me though, the time heist was so much fun and was refreshingly different after all the fighting in Infinity War.

If it had been a single timeline with a closed loop then it wouldn’t be as good cus Cap would have gone back and not interfered with anything.

Cap probably went back to a different timeline, married Peggy, kicked some Hydra ass, saved Bucky and then grew old and came back to our timeline with the shield to pass on to Sam.

It was a beautiful ending and a few plot holes aren’t going to ruin it for me.


Yeah, I also enjoy the movie, and although the Cap timeline did bother me, the ending does make me smile; that dance promise...

Not all time travel movies have plot holes, there are titles like "Primer" and "Looper" that in my opinion does it well.


I don't understand why once they got the time stone didn't use it to rewind time , there were many options to defeat Thanos once they had all the stones instead of snapping him into dust , another would have been to give Hulk the power stone and punching Thanos into oblivion or use the mind stone to make him brain dead and live the rest of his life like a vegetable , also it seems the writers created their own time travel rules for convenience.

Another thing i don't get is : from now on every MCU movie is set from 2023 onward starting with FFH?


I guess there are some possible explanations.

- Using even one infinity stone would probably still be too powerful, remember the ending of the Guardian of the Galaxy, they need to share the burden among all of the team. It doesn't matter for Tonny if he used one or all six.
- There are some candidates that can use the stones safely; Thor, Hulk, and Captain Marvel. I think Hulk should be the one most appropriate, if only for the reason that he gives before he uses it in the movie. But by this time Hulk has already been weakened for using it once, and don't forget that "The Professor" is not as strong as the original Hulk.
- And even then it doesn't matter for Tonny. None of the appropriate candidates are near him, while Thanos is right there in front of him. Rather than risking running away to get to Thor or Captain Marvel, he decided to use it on the spot. One or six doesn't matter, it would probably kill him anyway, might as well use all six to kill all of Thanos army at the same time.


That's not really true , Dr.Strange used the Time Stone multiple times and nothing happened to him , Steve used the Mind Stone in EG to subdue someone (i can't remember who it was) and nothing happened to him.


It was on himself:)


Could I argue that for those two they don't take the power of the stones fully instead just harnessing it? Mind stone was stuck inside that scepter so that anybody can use it without actually come in contact with it. The same with the time stone, it was housed inside that necklace and the sorcerers could only use it using sorcery.


Probably the governments would retcon the current year and wind it back 5 years. The calendar is not permanent. It had been changed up a few times already.


Honestly, the time travel logic is allowed to be funky, in my book, since its secondary (and most resonant) purpose was to serve as a nostalgic victory run through the franchise's short but rich history.

Like fan service, but not the shitty, lazy kind.


It's a comic book movie anyway. Not to be taken too seriously. Entertainment first, logic and consistency at the back seat. Truly faithful with the original comic books' spirit actually. Which is why Marvel is so successful.

Stan Lee would be proud.


The time travel stuff is nonsense. The sooner I accepted that the better the movie was, and I think giving Steve Rogers a satisfying ending is way higher on the film's list of priorities than making sure the goofy science is kept in check.


Really? I felt the time travel in this was a lot better than most other time travel stories. Travelling to separate realities explains why they couldn’t just change the past and it allows them to avoid a lot of time travel paradoxes. That way, the current timeline can still be neat and tidy. That’s just my opinion though, I thought it was pretty tight and consistent with its in universe rules.


Unfortunately, as with most time travel stories, this is one of those stories where the more you think about it, the less sense it makes.

I would have been OK with it if they hadn't had Steve stay in the past, marry Peggy, and become an old man. That just creates all sorts of havoc. For one thing, what about the guy Peggy was supposed to marry and have kids with? For another (as someone elsewhere pointed out), this Steve knew every historical event from 1940 onward - did he just let 9/11 happen? All the assassinations of the 1960s? That's kind of lousy.

Finally - IMO the tragedy of Steve's past gave his character texture and relevence. The idea that he just went back and gave himself the life he always wanted, just because he could, strikes me as uncharacteristically selfish of Captain America. It's a cheat - especially egregious coming from a guy who spent his entire existence being "a good man" and telling everybody to "move on".

It reminded me very much of the cheat that happened on the TV show "Quantum Leap". The main character, Sam, had an older brother who had died in Vietnam. That tragedy colored a lot of Sam's character.

Then, of course, the writers had Sam go back in time at the beginning of the second season and his brother's death in Vietnam was prevented. That baffled me. It basically erased an entire season's worth of texture that Sam had gained by having gone through a tragedy. There was no reason for it.

I would have been much happier if Steve had come back to the present and tracked down Sharon Carter. That would have been the honorable thing to do.


I completely agree with you regarding the character of Steve Rogers. I will just talk on the time travel points you raised.

Steve travels to a different reality that does not affect this reality so nothing he does there can affect the current reality. I think after he lived his life to fruition there, he simply returned to this reality.

As for preventing world events, there’s no indication that he didn’t. Given his time character and his knowledge, we could probably assume that he did all sorts of things in that second reality after marrying Peggy to steer the world to a better future. But ultimately, everything he does will only prevent events happening in that reality and does not affect the one he came from.

To this extent, Peggy’s future husband is no longer relevant. In our reality, she still marries that man and grows old with him but in the new reality Steve lives in, those events never happen. A new future is effected there.


i agree that if we go by the rules that the movie lays out, old steve should not be there.
but i think there is a simple explanation.
& that is that old man steve has not been living in the same time-line as the events we just saw.
he went back after restoring the stones, and lived his life.
then, at a point in his alternate timeline when he knew he'd just jumped to the past in the endgame time-line, he used his spare pym-particles to jump to his old time-line to say goodbye to sam & give him the shield.

this may be a bit of hand waving, but it is shown that steve grabbed excess pym particles when he was in the lab after seeing peggy, i believe.


Yeah he did grab extra pym particles so he could have came back whenever he wanted. And I agree that Old man Steve was not apart of the events that we saw. Old man Steve probably retired after Civil War or Infinity War because he had to form a bond with Sam in order to pass the shield to him and also during the war Thanos practically destroyed his shield, yet when he gives his shield to Sam it's almost brand spanking new, so from that I concluded that Old Steve didn't participate in the final war with Thanos. Frozen Steve that would be found in 2012 is the one who was apart of the events we saw.


I have a new explanation! Old man Steve is actually not Steve at all. He's... 2012 Loki in disguise! Afterall, Loki is the God of Mischief!


You could be right! LOL


Hm I like your theory but for the alternate reality Steve to be old, it would have to be way into the future as he would still be frozen. All things indicate that it was this Steve that had the happy life with alternate Peggy.

My theory is that it is the same Steve as the one who’s been through every mcu journey with us including endgame. When he went to return the stones, he stayed in the alternate reality to marry Peggy and stayed there. There’s no reason Howard stark from that reality couldn’t have made him a new shield. He could’ve effected all sorts of changes to history in that time line (Vietnam war, Iraq war, preventing 9/11). And then when Peggy passed away, he chose to return to his real timeline to pass his shield on to Sam. At this point, he would’ve felt content to return as the alternative reality’s Steve would be unfrozen and fit to carry on his legacy.


I thought the time travel aspects of this film were absolute garbage nonsense. I'm shocked more people haven't complained about it. I'm shocked that most critics gave this film their stamp of approval despite the time travel issues.

The main time travel related gripe that most people seem to have an issue with, is Captain America returning to the past to live with his former love. This was the smallest of the issues I had.

For example, time travel is not the same as space travel. How in the world did Hawkeye and Black Widow travel across space to retrieve the soul stone? Neither owns a spaceship, or knows how to operate one.

How do they know killing Baby Thanos won't work without testing it first? Science is about trial and error.

According to this movie, changing the past just results in creating/altering other timelines/realities. So, They're messing up multiple other realities to save our own? Not exactly a heroic thing, and pretty damn selfish really.


I’m going to have a go at responding to some of criticisms and hopefully improve your experience with the film but if ultimately you decide you still hate it, that’s fine too.

Captain America: Steve took extra pym particles so there’s nothing stopping him from returning to his present timeline as an old man after he had lived a long fruitful life.

Hawkeye and widow: they traveled to Morag 2014 with nebula and rhodey. From there, they branched off towards Vormir using the Milano (which we saw was also shrunken for easy transport. Further we saw in gotg2 that the Milano can do space jumps so it wouldn’t have been hard to get to Vormir if they knew how). Rocket had been with them for 5 years so it isn’t completely unbelievable that he would’ve shown them how to fly the Milano in that time.

Killing baby thanos: the science of the movie doesn’t support this hypothesis. It’s clear that banner and stark understood the delicacies of time travelling in the quantum realm. That is they knew scientifically that they are travelling into alternate realities and any action in those realities will only change that reality. I guess the question then becomes why not help that reality by killing baby thanos there? The movie only shows us the events of this reality, maybe cap does warn all other realities later when he returns the stones.

Messing up realities: not exactly. Cap returns all the stones back to the moment they were taken. And it isn’t beyond the realm of belief that while returning them, he would’ve warned them about the mad titan. Also, the way the movie panned out, saving our reality also saved morag 2014’s reality because thanos no longer exists in that reality.

Hopefully I changed your mind on some of these issues.


Thanks for the reply. First, I didn't hate the movie, but I can understand why you would think that based on my post. I think it's a great super hero movie. I also just happen to think it sucks from a time-travel-movie perspective.

I'm fine with Captain America staying in the past, I was just pointing out that others seem to have an issue with that.

Hey, thanks for explaining the Widow/Hawkeye space travel issue, that was a huge issue I had.

I think a another big issue for me, was that, with a 3 hour running time, I would have liked for them to explain their time travel rules/theories a little better. A little more trial and error would have been nice. (I mean, if your movie is going to spit in the face of several other time travel movie, it should be explained and shown VERY well, IMO).

"Cap returns all the stones back to the moment they were taken".......So they say, but I have ALOT of doubts and questions about his ability to do that. It took several teams of Avengers to go get them in the first place, and now Cap alone is going to return them all? He's going into Asgard, alone, and going inject Natalie Portman?

Anyway, Thanks again for the reply, and for clearing up at least one of my issues with the movie.