In Showtime's The Woman in the Wall, Ruth Wilson's Lorna Brady is not right in the head... or so we're told.

The dark and twisty trailer for the upcoming thriller series, which EW is debuting exclusively below, introduces us to the plight of Lorna, a woman from the small, fictional Irish town of Kilkinure, who wakes one morning to find a corpse in her house. Lorna has no idea who the dead woman is or if she had anything to do with her untimely end, mostly because Lorna is someone who has a tendency to do dangerous things while sleepwalking, says Wilson.

"We find Lorna waking up in the middle of the road surrounded by cows, and you realize this woman is someone who often sleepwalks, and that, as the show quickly reveals, is from a trauma in her past," Wilson tells EW. "She was at the age of 16 sent into one of these mother and baby homes because she had a child, she was pregnant out of wedlock, and she was basically put into one of these homes, and often there was forced labor in these places. And then when her child was born, it was taken from her and she has no idea really what happened to that child. Is the child dead or alive, and where has it gone?"

Chris Barr/SHOWTIME

She continues: "And then, you see her on a mission. It's why I loved her — she's someone that is a survivor, and because she is an outsider, too, she in some ways hasn't got anything left to lose, so she's going to fight for justice. So, initially, as an audience you'll think maybe she's in an act of revenge or she's a murderer, but as you watch the series, you come to realize that she's on a greater mission than that."

But, thanks to her grim discovery after a night of sleepwalking, Lorna decides not to let herself sleep again. So, as her nights become days and days become nights, Wilson teases: "You realize that she's a somewhat unreliable narrator in the show because you're not quite sure as an audience what's real and what's not... and neither is she."

Though the story is fictional, it's inspired by Ireland’s very real and scandalous Magdalene Laundries, the Catholic Church-run institutions for what the church deemed "fallen women" that often separated newborn babies from their mothers. It also follows Detective Colman Akande (Daryl McCormack) — a man with his own haunting secrets — who is on Lorna’s tail for a crime seemingly unrelated to the body she has discovered in her home. As Colman searches for a murderer and Lorna searches for her daughter, their paths collide in unanticipated ways.

It all amounts to a story that is at once a crime thriller and a gothic horror, with a dash of black comedy thrown in. Says Wilson, "I thought it's such a smart way to get a really quite important story out there and kind of hide it through genre and get people hopefully attracted to the material for those genre tropes, for the horror of it, for the crime in it, for the black comedy humor in it, which is also quite Irish in its sensibility. But actually underneath you are drawing the audience to a more important story at the heart of it and hoping that they will start to dig a bit deeper into that or learn something else from it as well."

SHOWTIME

Created and written by BAFTA Award nominee Joe Murtagh, the series also stars Simon Delaney, Philippa Dunne, Mark Huberman, Hilda Fay, Frances Tomelty, and Dermot Crowley. The Woman in the Wall will premiere on streaming and on demand for Paramount+ subscribers with the Paramount+ with Showtime plan on Friday, Jan. 19, before making its on-air debut on Showtime on Sunday, Jan. 21, at 9 p.m. ET/PT.

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