An ordinary housewife in 1970s Belfast takes on both the IRA and the British Army in order to put an end to the city's violence. Bernadette decides enough is enough when a friend is killed in front of her young son's eyes. She speaks out in public, but the Protestant press turn her words into an anti-IRA campaign. She is ostracised by her own community, until she decides to talk directly both with the IRA and the British government. Things get complex when her daughter's boyfriend is arrested as a terrorist.