The "X-Men"-themed FX series "Legion" has got a launch window, if not quite a launch date – February 2017, as announced via the show's official Twitter feed.

The tweet comes with a 30-second teaser that restates the show's core premise – that its central character thinks he is mentally ill, and does not suspect that he is in fact an incredibly powerful mutant, (who might also be mentally ill.)

The series stars Dan Stevens, best known as the ill-fated Matthew Crawley in "Downton Abbey," as David Haller, a character described as a "troubled young man who may be more than human" and who has to contend with voices and visions that may prove more real than he first suspects.

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First announced in October 2015 alongside another potential X-related TV series, the now-abandoned Hellfire, "Legion"

has been developed by Noah Hawley (“Fargo”), who serves as an executive producer on the series as well as the writer and director of its first episode.

The show's main character was first introduced in 1985 in Marvel’s "New Mutants" #25 as a young man with dissociative identity disorder whose personas each control one of his several mutant abilities. In the comics, it is revealed that David is the son of Charles Xavier and holocaust survivor Gabrielle Haller, and while it is uncertain how much of this will be carried over to the TV series, Hawley did say "we are true to the origins of this character," at the show's panel at the 2016 New York Comic Con.

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Starring Dan Stevens, Katie Aselton, Jeremie Harris, Bill Irwin, Rachel Keller and Amber Midthunder, season one of "Legion," will consist of eight episodes and debuts in February 2017 on FX.