Avengers: Endgame time travel and the one fatal flaw

I’m just going to say it – I didn’t love Avengers: Endgame. It’s a good movie, but I can’t gush about it, and it took me a few days to realize why. The problem is this new version of time travel. It’s broken.

Time travel is a tricky business – in fiction that is. Putting aside the fact that it’s not possible in modern physics, when your story involves time travel, things get dicey. Up until now, there have been two predominant time travel theories, which I call the Back to the Future theory and the 12 Monkeys theory. We’ll start with the latter, because it’s easier.

Movies in time

The movie 12 Monkeys demonstrates that time travel is possible, but it is not possible to change the past. The reason is because if you changed the past, what you changed would have been the past. Simple. You can try to go back and kill Hitler as a baby, but you will fail because that did not happen. This theory of time travel suggests that there is one timeline, and that’s it. There are no parallel universes, you can’t change things even if you wanted to. You don’t know why you were unable to – but you would surely find out if you tried.

Then, there’s Back to the Future. In that movie, you can travel back in time and you can change the past, but if you do, the present you travel forward to is changed. You flow along that same timeline along with everyone else. There are a few hiccups to that theory – why, when old Biff stole the DeLorean and went back to give the almanac to himself in the past, did he come back to the prime timeline and return the DeLorean with no problem?

Now, let’s talk about Endgame. First of all, Endgame does a terrible job at explaining its own temporal mechanics, and so it took me a few days and several articles around the internet to figure it all out. But, near as I can tell, this is how it works.

How it works

You can’t change your past. It already happened. If you travel to the past and change anything, you are creating a new timeline in which the thing you changed happened. But, nothing happens to your timeline. When you return to the future, you’re returning to your timeline. The movie dictates that when you take the stones, you’re creating alternate timelines. In reality, simply being in the past creates a new timeline because by being in the past you are a change. Call it the butterfly effect if you want.

Because of these temporal mechanics, Loki can disappear with the tesseract, and Old Nebula can kill Young Nebula without also dying. That’s why Thanos can come forward in time. The prime timeline stuff still happened because Young Nebula and Thanos B were from a different, new timeline that was created when the Avengers headed to the past. In that timeline, Thanos will never collect the stones or snap away half of existence, but in this timeline, he already did, but it was the Prime Thanos, not Thanos B.

Confused yet? Because here is the main benefit for Endgame time travel 101: No consequences. What made movies like Back To The Future, and even TV shows like Stargate SG-1 and Star Trek Every Series Ever Made interesting was the idea that the characters who travelled back into time had to be very careful in the past so as not to affect their own future. In Endgame, screw it, we can have a party, shoot Thanos in the head, kill baby Hitler, and kick Marilyn Manson in the balls 86 times, and then go back to the future, and nothing will have changed. It’s all good in the hood.

In the “real” world


Writers Christopher Markus and Stephen McFeely point out that they consulted physicists as to how time travel would work. Turns out Back to the Future is wrong – so they say. Of course, as mentioned previously, no one has actually travelled through time yet, so I think it’s hard to say we know this with any certainty. Then again, no one had taken a photo of a black hole yet, and it turns out Interstellar was almost exactly spot on. Go figure. Honestly, we don’t know what would happen. So we have to revert to logic and storytelling to figure it out.

According to Markus and McFeely, “If you have six MacGuffins and every time you go back it changes something, you’ve got Biff’s casino, exponentially.” Well, not necessarily. And that’s where the consequences come in. With six alterations to the timeline, you do have to be extra careful not to mess anything up. You could certainly devote more time to recovering the stones, and less time on Thor yammering on about how sad he is.

But the problem with no-consequences storytelling is there is no need to be careful. You can have a racoon stab Natalie Portman in the butt and run screaming through the castle, and no one will care. You can snatch the Time Stone from the Ancient One, and just deal with it, broski. That’s her problem. Captain America didn’t have to go back and put the stones back. It only really helped those alternate timelines which honestly none of our heroes should really give a crap about.

This is getting old

Which makes the end scene with Old Cap so confusing. Because even in the loosey goosey rules of time travel in the MCU, they still managed to break one before even rolling the credits. If Steve Rogers travelled to the past, he should not have been in that same timeline to wind up on that bench 70 years later. Although, maybe that was the plan all along…

Put simply, time travel, as it exists in the MCU is basically little more than lazy writing, and frankly, it made me enjoy the movie less than I should have. If there had been actual stakes, except for “gosh can we get all the stones” it would have made a much more compelling story. That’s why Back to the Future persists as a classic almost 35 years later. It’s because there was real drama.

Writing Infinity War and Endgame must have been a brutally monumental task. Giving every key character enough story to justify their presence within the confines of a 181 minute movie is an incredible achievement. And let’s face it, the last hour of Endgame might be the greatest thing to happen on a movie screen in history. But the two hours leading up to it diluted the movie in my opinion, and it did so for what seemed like nothing more than just lazy writing. Avengers had an opportunity to keep audiences on the edge of their seat for three full hours, but they dropped the ball.

So, should you skip Avengers: Endgame? Well, chances are if you’re reading this, you didn’t. By all means, you should enjoy it. One of the benefits of this method of time travel is you get a lot of fan service moments – Cap fighting Cap, Loki living to fight another day, Stark chatting with Dad about fatherhood, Cap running into Peggy. These are all really neat moments, but they’re only made possible by the fact that nothing bad could happen in the present. Maybe that’s a good thing – maybe 3 hours of the drama we got in the last hour would have been heart attack-inducing. Maybe they did it for our safety. It’s hard to argue that point.

Anyway, now we have three cinematic theories of time travel, and sadly, no practical ones. It’s time for the philosophers and the geeks to take over. Which theory do you enjoy watching the most? Which makes the most sense to you? 12 Monkeys, Back to the Future, or Avengers: Endgame? Sound off in the comments and hash it out.