Twenty-five years after a peace agreement was reached, Once Upon a Time in Northern Ireland shares intimate, unheard testimonies from all sides of the conflict. It weaves together the personal stories of ordinary men, women, and children who were drawn willingly and unwillingly into a conflict spanning over thirty years. The series mixes extraordinary archive footage and emotionally compelling first-person testimonies to create an intimate, multi-generational portrait of Northern Ireland's past, present, and future, emphasizing understanding and empathy for all points of view.