Even before Avengers 4 has hit theaters, there’s already been a juicy plot twist. According to The Wrap, Katherine Langford, star of Netflix’s 13 Reasons Why, has filmed scenes for the upcoming Marvel movie. Who is she playing? That’s the twist—we don’t know.

Over the past several months, there’s been plenty of speculation over how the film will unfold and who will survive the final showdown with Thanos. But this is the first time we’ve heard about Marvel hiring for a new role.

Considering it’s been such a closed secret until now, it must be big. It’s unlikely Langford, who is an up-and-coming star in Hollywood, would join the cast for a throwaway role. Will her character eventually evolve into a new hero?

We won’t know until Avengers 4 hits theaters. Or, we might get a glimpse at her character when Marvel drops the first teaser before the end of this year. The film will hit theaters on May 3, 2019.