FX's X-Men-Based "Legion" Enlists Dan Stevens, Aubrey Plaza & Jean Smart

Following news that Rachel Keller would play the female lead in FX's upcoming "Legion" pilot, The Hollywood Reporter has learned that three more actors -- Aubrey Plaza, Dan Stevens and Jean Smart -- will star in the series.

Dan Stevens will star in the series as David Haller, described as "a haunted man, trying to find his way back to sanity, but he's getting tired and is about to give up when he meets the girl of his dreams." Stevens is coming off a lengthy stint as Matthew Crawley on the acclaimed drama "Downton Abbey." In the X-Men comics, Haller's codename is Legion and he's the schizophrenic son of Professor Charles Xavier and UN ambassador Gabrielle Haller.

Aubrey Plaza, most known for her role as April Ludgate on the sitcom "Parks and Recreation," will play Haller's best friend Lenny. Lenny has lived a life of substance abuse, but "knows that any day now her life is going to turn around" thus making her an "impossible optimist" with a "rough demeanor.

The series comes from "Fargo" showrunner Noah Hawley; both Smart and Keller are "Fargo" alums themselves. Jean Smart, who also starred in the sitcom "Designing Women," will play Melanie, a "nurturing, demanding therapist with a sharp mind and unconventional methods." Both Lenny and Melanie appear to be original characters created for the series.

"Legion" is in development at cable network FX, with "Fargo's" Hawley on board as a producer. According to the official description, "Since he was a teenager, David has struggled with mental illness. Diagnosed as schizophrenic, David has been in and out of psychiatric hospitals for years. But after a strange encounter with a fellow patient, he's confronted with the possibility that the voices he hears and the visions he sees might be real." Production on the "Legion" pilot will begin in March.

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