We’ve heard some big Avengers 4 theories over the past few months and this latest one is a doozy. With a deal between Disney and Fox all but done, there’s one way Marvel Studios could believably integrate the X-Men into the Marvel Cinematic Universe—and it involves Thanos.

The theory basically suggests there will be a second “snap” in Avengers 4—perhaps to undue the damage done by Thanos—that will awaken the mutants we’ve come to know as X-Men. It sounds crazy, but it just might work.

The theory argues that Scarlet Witch and Quicksilver are mutants, despite being called “miracles.” Regardless, they were created by being exposed to the Mind Stone. Here’s where the theory comes in:

In Avengers 4 it seems likely that the first snap will be undone by a second snap. So upon the second snap, what if it creates a shockwave sending radiation throughout all of REALITY and TIME using the MIND stone to alter beings’ physiology. Altering the main timeline and creating the mutant gene.

This would make it so that the Avengers directly cause the X-Men.

Essentially, the theory is saying that the Mind Stone woke up a latent gene inside Scarlet Witch and Quicksilver, allowing them to tap into their powers. The combined power of the Mind, Reality, and Time stones could have a similar effect on others across the globe (and the wider universe).

Going this route would retcon a lot of mutant history, but it does sound like a feasible way to introduce more X-Men to the MCU without getting into the complexity of the multiverse. Instead, these mutants will have been around all along, with their presence now coming to the fore following a second snap.

Whichever route Marvel goes, incorporating X-Men into the MCU is going to present plenty of hurdles. But it would be an easy way to get the ball rolling—and a post-credits stinger attached to Avengers 4 featuring Wolverine would make audiences go wild.