*WARNING: This article features references to the events that transpire during Avengers: Infinity War. If you haven't seen the movie, and don't want to be exposed to spoilers, wait until AFTER you see the movie to read this article.
The events of Avengers: Infinity War has Marvel fans the world over asking one simple question:
What now?
With an ending unlike anything seen in a superhero movie before, Avengers: Infinity War sets up Avengers 4 in an interesting way. The ending suggests that Thanos will continue to play a role, but that's really all we know. Until a title is announced, and a trailer released, all anyone can do is make predictions. Here is what I believe will transpire in the next Avengers movie:
1. Most of the "dead" characters won't stay dead
As one would expect, a good amount of characters die in this movie. However, while some of the deaths were expected (Loki, Vision, Heimdall), other ones (Black Panther, Dr. Strange, Bucky, Scarlet Witch, Spider-Man, all of the Guardians of the Galaxy except Rocket, Falcon) were not. However, most of these characters (specifically the latter group) are unlikely to stay dead. The latter group was killed by Thanos' infamous snap after assembling all of the Infinity Stones, so it is very likely that the damage will be reversed by the time Avengers 4 is over. The only member of the latter group who is uncertain to come back is Gamora, who was killed before Thanos' snap.
2. Red Skull and Captain America meet again
One of the biggest surprises of the movie came in the form of the return of the Red Skull, who was looking after the Soul Stone. This opens up the opportunity for Captain America to have one last face off with his arch-enemy. It would also be interesting to see if Red Skull decides to return to Earth, as he no longer has to watch over the Soul Stone.
3. The story will be about undoing the damage
Despite the downbeat ending to the movie, you know that somehow the heroes will come out on top in the end. Thus, the majority of Avengers 4 will be about cleaning up Thanos' mess. Whether it is done by time travel or the Infinity Stones (which still appear to be intact) remains to be seen, but this tale will have a happy ending (for the most part) one way or another.
4. It will lay the ground work for the Fantastic 4 and X-Men
The acquisition of the Fantastic 4 and X-Men film rights couldn't have come at a better time, as far as introducing them is concerned. Even if the Avengers defeat Thanos and revive most of the other heroes lost, the universe won't be the same as it was before. Thus, the future introduction of the Fantastic 4, the X-Men, and the mutant race can be explained as consequences of Thanos' abuse of the Infinity Stones or the heroes possible exploits in time traveling.
5. Captain Marvel will be the one to defeat Thanos
In the post-credits scene to the movie, Nick Fury sends out a message before dying due to Thanos' Infinity Snap (yes, that's what I'm calling it). That message was for Captain Marvel, as seen by the symbol shown on Fury's pager. Described by Kevin Feige as the strongest hero in the MCU, look for Captain Marvel to cement herself as the new face of the franchise by taking down its greatest villain.
6. Dr. Strange's plan will be revealed
Arguably the most shocking moment of the film (aside from a bunch of the heroes dying) is Dr. Strange willingly giving up the Time Stone to Thanos. Prior to this moment, Strange revealed to his group that he looked into over 14 million (14,000,605 to be exact) possible futures, and only one has them defeating Thanos. It appears that allowing Thanos to (for the moment) complete his goal is part of the plan, but rest remains to be seen.
7. The original Avengers will trade their lives for the others
It is no coincidence that the original members of the Avengers (Captain America, Hulk, Thor, Iron Man, Black Widow, and presumably Hawkeye) are among the group that did not perish after Thanos' Infinity Snap. This will undoubtedly lead to the heroes who started it all having one last stand against the Mad Titian. I firmly believe that the climax of the film will see them sacrifice themselves in order to resurrect the other fallen heroes in a sort of passing the torch moment. On top of that, they will finally say "Avengers, Assemble!".
8. It will hint at the next big villain
Thanos may ultimately fall, but someone will surely take his place. The MCU isn't itself without a big villain to build up to, after all. The question is who that villain will be.
Is the Red Skull reveal a sign that he will be that villain?
What about another destructive force like Galactus?
Could the Skrulls have a greater impact after appearing in the Captain Marvel movie?
Could villains associated with the X-Men and Fantastic 4 such as Dr. Doom or Magneto take on that role?
Zemo is still (presumably) out there, so could it be him?
Dormammu?
Mephisto?
The Beyonder?
Regardless of who it is, there will certainly be life after Infinity.