Since Marvel continues to keep tight tabs on the details of its upcoming movies, fans theorize what may happen next in the Marvel Cinematic Universe, and in the case of one theory involving Doctor Strange, it makes sense that he could make an important appearance in the past to save the future.

A Reddit user posted a theory over at the properly titled fan theory subreddit of Doctor Strange’s possible role in next year’s Captain Marvel. They suggest that the Sorcerer Supreme will make an appearance in the movie, but not to interact with Carol Danvers. Instead, Strange will contact Nick Fury.

“I believe he’ll appear in the CM movie and tell Fury it is vital for him to carry around with him the pager to contact Captain Marvel,” posted Reddit user WamsyTheOneAndOnly. “He warns him of an event in the future referring to the people turning to dust without warning, this is why Fury’s instant reaction to seeing Maria Hill turn to ash was to run to the pager, but what our good friend Sorcerer Supreme didn’t mention was the fact that he does not survive hence the ‘Mother Fu…’ at the very end. We should also take note that the way he says it isn’t panicked or scared, he’s confident that Strange knows what he’s doing.”

In Avengers: Infinity War, it’s clear that Doctor Strange knows how everything will go down hence the reason he gave up the Time Stone to then say to Tony Stark that “it was the only way.” It’s also possible that Strange went back in time — since Captain Marvel takes place in the 1990s — via astral projection during his time reviewing all the possible scenarios to beat Thanos. The only issue some on the Reddit thread had was the notion that Fury would recognize Doctor Strange because his name was mentioned as a threat to Hydra in Captain America: The Winter Soldier, but the head of SHIELD may also simply take the word of a time-traveling astral ghost since that’s not something he sees every day.

Marvel movie fans will have to wait until March 2019 for the release of Captain Marvel to know for sure, but there could be a hint in the upcoming Ant-Man and the Wasp, which comes out on July 6.

There are plenty of theories on how the heroes will win in Avengers 4, and most of them, like this theory, deal with time travel.