Cushla (Lola Petticrew) is a young Catholic schoolteacher whose life in 1975 Northern Ireland is shadowed by the Troubles. Amid curfews, bombings, and betrayals, she works nights in her family's pub, serving both sides and British soldiers, when she meets and falls for Michael (Tom Cullen) - an older, married Protestant barrister. Their affair is intoxicating and dangerous. Cushla's world is full of defiant spirits: her drunk, sharp-tongued mother Gina (Gillian Anderson), her lively pupils, and beloved colleague Gerry (Oisin Thompson). As the forbidden love between Cushla and Michael deepens, violence looms and tensions rise. Cushla is pulled between duty and desire, family and freedom.