FX’s upcoming X-Men series, Legion, has brought in another new cast member in the form of Jeremie Harris.

The Hollywood Reporter has word that the relative newcomer, best known for roles in The Get Down and Bessie, has landed the gig of Ptonomy, a recurring role described as “an outsider by nature, stand-offish and sardonic who is a former child prodigy who feels trapped in the past”.

Legion will centre of David Haller, played by The Guest’s Dan Stevens, a young man diagnosed as being schizophrenic but who soon begins to realise that maybe the voices in his head aren’t quite as imaginary as some would have him believe. In the comic book realm, David is revealed to be the son of Charles Xavier. In additional to Dan Stevens, the show will also feature Aubrey Plaza, Jean Smart, and Rachel Keller. Fargo’s Noah Hawley is writing the pilot for the show and will serve as an executive producer alongside Lauren Shuler Donner, Bryan Singer, Simon Kinberg, Jeph Loeb, Jim Chory and John Cameron.

The pilot for Legion is set to head into production at the end of March.