A famous author dies in an apparent suicide, but her final words to her twin daughters suggest something darker. Becoming fixated on the man they believe has murdered their mother, they vow to avenge her death. One night at the National Library of Wales they close in on their target, but are disrupted by a night porter who becomes unwittingly caught up in the saga. Directed by award-winning director Euros Lyn (Torchwood), starring Catrin Stewart (Doctor Who) as the twin sisters, and based on Fflur Dafydd’s bestselling novel.