We still have a good few months until we get to Avengers: Endgame, which means we have time to speculate on how exactly Marvel plans to follow up the epic Infinity War.
The last film ended on a cliffhanger, with alien villain Thanos (Josh Brolin) obtaining all of the Infinity Stones he needed to wipe out half of the universe in a huge act of decimation.
And decimate he did - with half of our heroes being turned to dust.
Endgame sees the few survivors - including Iron Man, Steve Rogers, Black Widow, Hulk, and Thor - try to figure out how they come back from the devastating conclusion to the last installment.
Here, Mirror Online have gathered the theories gaining the most steam online, whilst also examining how likely they are at really happening.
Avengers 4 theories: What will happen in Endgame?
1. Time travel will reverse the Decimation
Pretty much everyone is in agreement that time travel will be the method to undo Thanos' wiping out of half the universe's population - and many Marvel fan favourites.
Doctor Strange may or may not have done something with the time stone, or have foreseen that one possible future where Thanos is defeated and how time travel stopped it.
Alternatively, some think that Ant-Man's shrinking abilities that allow him to cross the multiverse into the Quantum Realm (where Strange has also been) and travel through time to undo what Thanos did.
Either way, Black Widow and Steve Rogers "have a plan".
Or finally, Thanos himself will undo what he did - more of that below.
2. Gamora will return from the dead
Thanos throwing Gamora to her death on Vorimir in Infinity War was one of the most shocking moments in the film.
Now that it has been confirmed that the sequence between Thanos and child Gamora at the end of the film in a watery and orange-tinted world actually took place inside the Soul Stone, it seems this may be the key for the leading lady of the Guardians to return to the land of the living.
Did the Soul Stone trap Gamora's soul inside when Thanos sacrificed his beloved adopted daughter to gain its power?
Either way, expect an appearance from Zoe Saldana in the film.
3. Bucky becomes Captain America
This has been assumed by many Marvel fans for a while, as Bucky has taken an increasingly prominent and heroic role, along with the fact that in the comics Bucky took on the mantle of Captain America after Steve Rogers was killed off for a while.
The only other alternative is Falcon, who was also Cap in the comics too, but Bucky has got the most attention so far. Both Bucky and Sam Wilson were decimated in the finale of Infinity War, but there's no way that those deaths are gonna stick!
The only issue in the way is the report of a Winter Soldier/Falcon series on Disney+, unless that's actually a Cap and Falcon mini-series.
4. Pepper Potts will become the superhero RESCUE
This has been seriously hinted at by actress Gwyneth Paltrow herself, as she has been wearing a green-screen suit on-set, indicating she will have a CGI outfit on, and she's hinted at being more involved in the action.
In the comics, Pepper gets her own armour and becomes the heroine Rescue, so will she get to fight alongside her fiancé Tony in their armours?
We know she survived the Decimation so she will definitely be back.
5. Loki will be back
Thanos may have strangled the God of Mischief to death in front of brother Thor, but is that the last we will see of the trickster?
With a Loki mini-series confirmed for Disney+, we suspect that Loki has one more resurrection up his sleeve.
However, many felt Loki's sacrifice was the ideal end to his character arc, so maybe Marvel has another way in which the character will return.
Loki TV series confirmed for new streaming service Disney+ with Tom Hiddleston
6. Thanos will find redemption
As the crew and Josh Brolin have emphasised what an emotionally complicated and rich character Thanos is, it would be great if he somehow redeemed himself at the end of the whole saga.
In the comic event Marvel:The End, Thanos destroys the universe but undoes it out of loneliness and love for his unrequited amour, Lady Death, but loses his life in the process. This would be an emotional climax that doesn't devolve into the standard CGI punch-up, but with the absence of Lady Death, we think it could be born out of his complicated relationship with Gamora.
What if Thanos sacrifices his soul to the stone to bring back Gamora and undo all he has done?
Either that or other adopted daughter Nebula (Karen Gillan) will finish him off in vengeance.
7. Steve Rogers will die
Many have already assumed that Steve Rogers will be written out of the MCU, and actor Chris Evans has pretty much confirmed it himself, until recently suggesting he wasn't entirely done with the role.
Evans' exit is logical as it would move the franchise ahead and all of Steve's arcs are more or less tied up or ready to end.
It will allow Bucky or Falcon to take up the mantle and a new era begin, but maybe, just maybe, Cap will get his happy ending and leave the door open for Rogers to return down the line.
Avengers 4: Chris Evans is "not done yet" with Captain America role
8. Iron Man/Tony Stark will die
There has been more uncertainty about Robert Downey Jr.'s future with the Marvel Cinematic Universe, but with Pepper, Happy and the young Harley from Iron Man 3 making a return, are these characters mainly present for Tony Stark's swan song?
Stark won't appear in Spider-Man: Far From Home alongside his protoge Peter Parker, with Nick Fury seeming to oversee the teen. Could Stark have been killed in Endgame beforehand?
This seems to clash with a certain leak, with Gwyneth Paltrow seemingly revealing that Tony and Pepper's ending, but maybe it's not as heartbreaking as we might think.
Gwyneth Paltrow may have just given us a major spoiler for the end of Avengers 4
9. The Avengers get a new line-up and new leader
This is definitely going to happen, with the MCU being changed forever, so we are already speculating on who will be left in the line-up. Beyond perhaps Black Widow, we doubt any Avengers will remain from the original line-up, with more of a focus on the next generation, such as Spider-Man, Captain Marvel, Bucky, Falcon, Ant-Man and the Wasp, and maybe Vision and Scarlet Witch too if Thanos' actions get undone.
In terms of leadership, many have touted Spidey, but would a kid really get the prized position? We think Captain Marvel is a stronger contender, or perhaps the King himself, Black Panther, and maybe a new base in Wakanda?
It's all to play for!
Avengers: Endgame is released on April 26, 2019.
What do you think is going to happen in Avengers: Endgame? Let us know in the comments below.
