Marvel Studios boss Kevin Feige recently confirmed that we’d soon be getting some Phase 3 casting news, and today has seen a very interesting addition made to Guardians of the Galaxy, Vol. 2 in the form of relative unknown Pom Klementieff. She’s been chosen for a “key role” in the sequel, though who exactly she will be playing is being kept a secret.

According to The Hollywood Reporter, “Marvel conducted a wide search for its mystery part, which called for an Asian actress, doing several rounds of chemistry reads.” Fans are already speculating that Klementieff is going to take on Mantis, a fan-favourite member of the Guardians of the Galaxy from the comic books, but we have no real idea as of right now.

James Gunn is returning to direct the Guardians of the Galaxy sequel which will see Chris Pratt, Zoe Saldana, Dave Bautista, Bradley Cooper, and Vin Diesel all reprise their roles.

An interesting titbit revealed by Variety is the fact that Dallas Buyers Club and True Detective star Matthew McConaughey passed on the opportunity to play the movie’s villain. The Oscar winning actor revealed earlier this year that he had read scripts from both Marvel and DC, and that he would be interested in a comic book movie role if it was the right one. For whatever reason, he clearly didn’t feel that way about Guardians of the Galaxy, Vol. 2.

Regardless, the sequel is currently set to be released worldwide on March 5th, 2017.