We went to see Avengers: Endgame this weekend (along with the rest of America). I understand that the movie was already on the long side, that the makers perhaps didn’t want to run any longer, but I wish they had included a post-credits scene or two to answer a few of the time travel questions I have.

SPOILER ALERT: Details of the Avengers: Endgame plot follow.
I have ideas about what might and might not work regarding time travel, so when I see a movie that uses this as a premise, I expect to have questions. After all, time travel is tricky. Anyone with any imagination finds the idea of revisiting the past intriguing, and I’m happy to say that despite some mistakes, Endgame used the premise well.
People see themselves or people they care for in some touching moments. Tony Stark has a charming talk about parenthood with his expecting father and Steve Rogers catches a glimpse of his love Peggy Carter. Fans also get to revisit places, events, and people they remember from other movies, including the attack on New York City from the original Avengers film.
Endgame even sets up its time travel rules in a way I completely agree with. When someone suggests they travel back to get the Infinity Stones before Thanos can use them, Bruce Banner explains that you can’t change the past, but you can change the future. So their plan is to get the stones to undo Thanos’ work instead of trying to stop his plan. Unfortunately, despite stating this rule quite clearly and even making fun of Back to the Future for not following it, Endgame allows some events that should have messed up the past in a big way.

The most obvious is that Thanos comes forward in time to attack the Avengers, leaving at a time before he has gathered the Infinity Stones and wiped out half the life in the universe. He is then part of a an epic and ultimately satisfying battle in which he is not only defeated, but destroyed. As in dead, gone forever, no more.
Even if Thanos had lived, it seems unlikely he would have gone back to when he came from and then lived out his life exactly as he had before. No matter how you look at it, the time line is seriously disrupted. Even if Captain America returned the Infinity Stones at the right time to undo such a disruption, the story doesn’t work. If Thanos doesn’t realize there’s a second Nebula running round, he will never be at the battle in the future that leads to his defeat.
This sort of time travel conundrum is a classic problem, and in this case, applies to many more characters than just Thanos. Gamora and Nebula both come forward in time with him. Future-Nebula kills past-Nebula, an act you would think would erase future-Nebula as well, but it doesn’t. How can she exist if her past self is dead?
We also see Gamora reject Quill but have no idea where she goes. She is already dead in Quill’s time line, but her father is no longer alive to sacrifice her when the time comes. And what about Loki, who escaped with the tesseract instead of going to Asgard with Thor to be punished? He must be out there somewhere, plotting… unless he isn’t. If there were any post-credits scenes, I thought for sure, there would be one about Loki.
The one change to the past that didn’t bother me too much was Steve Rogers’ decision to stay in the past and live the life he missed out on, but I’ve found that at least one fan more familiar with Captain America’s history than I am thought this was completely unbelievable.
Despite these problems, I recommend that you see this film. If you like superhero movies at all, suffer through Infinity War and then bask in the revel that is Endgame. This film is witty, moving, and powerful and my friends who said they were drained afterwards are not exaggerating. It really takes you for an amazing ride.
What did you think of Endgame?