Thanks to tsukikomew for the heads up.
Details of her role and the storyline for Season 3 are being kept under wraps, but in an earlier interview with Deadline’s AwardsLine, star Viola Davis said there will be “a new mystery” in Season 3, “and it’s going to be presented very quickly in the first episode.” Davis also added, with that new mystery, creator Pete Nowalk “explores the relationships in a much deeper way.”