The tricks and double-crosses from Loki came to a tragic end in Avengers: Infinity War. But a new theory argues that not only will he be back in Avengers 4, but his fate is tied to Thor’s sister Hela.

The theory presumes that at the end of Thor: Ragnarok, Hela didn’t die—she is the Goddess of Death, after all—when Surtur instigated Ragnarok. Rather, she is now residing in Hel, where Thor will travel after gaining access to the same cave he went with Selvig in Avengers: Age of Ultron.

There, he will convince Hela to bring his brother (and, technically, her brother) back to life following his untimely demise in Avengers: Infinity War. It’s unclear why Hela would bring Loki back at all, and the theory has no convincing suggestions. Perhaps Thor could promise Hela something in exchange.

The theory came to this conclusion by looking at previous set photos and cast interviews. Apparently, Tom Hiddleston, Chris Hemsworth, Tessa Thompson, and the stand-in for Rocket Raccoon were all spotted filming in England at the Durham Cathedral for Avengers 4. This is the same place Thor goes to when he has a vision for Ragnarok in Avengers: Age of Ultron.

We’ve heard multiple theories about Loki’s status in the Marvel Cinematic Universe since Avengers: Infinity War was released earlier this year, and this latest theory adds a new twist. Many previous theories have suggested that Loki simply tricked Thanos and didn’t actually die.

Either way, we know that Loki will be back in some capacity when Avengers 4 hits theaters next year, as multiple set photos have shown him at the Battle of New York from the first Avengers movie.

We’ll find out what Loki is up to when Avengers 4 hits theaters on May 3, 2019.