McDermott's character was killed off the anthology series at the end of the first season.
Season 2 began Wednesday night with a new setting and several Season 1 cast members such as Jessica Lange and Sarah Paulson returning in different roles.
"So thrilled to announce Dylan McDermott is returning to American Horror Story!" Murphy tweeted, without divulging any details about who he will play or when he will be seen on the show.
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