Drawing on newspaper reports of the day, Gillespie reminds readers of the times of optimism and despair which accompanied the great as well as tragic events. Years of Darkness covers landmark days such as Bloody Sunday, Bloody Friday, the Sunningdale Agreement, the Anglo-Irish Agreement, the Enniskillen and Omagh bombs and many others. However, the book also recalls some of the 'forgotten' atrocities of the Troubles, among them Coleraine in June 1973; the Strand Bar in April 1975; and the Ramble Inn in July 1976. The often graphic accounts of those who survived such events remind the reader of the human cost of the Troubles.

Years of Darkness provides an analysis of the main political and security developments. But much of its focus is on the impact of the Northern Ireland conflict on the ordinary person and on those who survived as much as on those who died.