Ever since the shocking conclusion of Infinity War, we've heard plenty of theories about what might transpire in Avengers 4.
We've heard theories about Nick Fury and Thanos, but we are yet to really get any insight into how 'Earth's Mightiest Heroes' might defeat 'The Mad Titan' in the final instalment of the saga.
One theory that has been doing the rounds on fan sites and social media for a few months revolve around Doctor Strange and the Time Stone.
As you will have seen in Infinity War, Thanos needed to collect all of the Infinity Stones in order to complete his goal of wiping out half of life in the universe.
He was partially able to achieve this by taking the Time Stones from Doctor Strange. And when we say 'take', we actually mean Strange just straight up surrendered the stone to the villain.
Or did he surrender the stone? After all, Strange only gave the stone over to Thanos after he saw that there was only one possible way to defeat him.
Did Strange manage to do something with the stone before giving it over?
Something that has been suggested is that Strange managed to go into the past or future to set off a chain of events that would help the Avengers triumph.
This is all just hearsay but Joe Russo, the co-director of Avengers 4, has subtly hinted that this theory might not be too far from the truth.
According to the Express, in the new illustrated companion book Marvel's Avengers Infinity - The Art of the Movie, Russo said:
The problem is, as you can imagine, as you gain control over these things, your story just goes haywire because why are there any stakes for the man who can control time, space, reality, your mind, your soul and power?
He can reset as many times as it'll take.
So you have to build in a lot of bumps in the road or maybe keep one stone away from him for long enough in order for the thing to have any dramatic structure at all.
Russo's words aren't exactly clear but it would suggest that one stone is the key to defeating Thanos.
Whether this turns out to be the case or not remains to be seen but it's certainly intriguing.