In Ireland, American lawyer Ingrid Jessner (Frances McDormand) and her activist partner, Paul Sullivan (Brad Dourif), struggle to uncover atrocities committed by the British government against the Northern Irish during the "Troubles." But when Sullivan is assassinated in the streets, Jessner teams up with Peter Kerrigan (Brian Cox), a British investigator acting against the will of his own government, and struggles to uncover a conspiracy that may even implicate one of Kerrigan's colleagues.