The story is told from the point of view of an unnamed young Irish Catholic boy living in a poor area of Derry. This novel-in-stories is about both the boy's coming of age and the Troubles of Northern Ireland, from the partition of the island in the early 1920s until July 1971, just after the violent Battle of the Bogside took place in Derry. The setting mirrors mid-twentieth century Derry leading into the Troubles. While the narrator is surrounded with violence, chaos, and sectarian division, Derry serves as the place where he grows up, both physically and mentally. Despite the surrounding events, the narrator's tone never slips into complete despair, but maintains a sense of hope and humour throughout.
The main focus of the novel is the young narrator’s gradual uncovering of a family secret and the effect of this knowledge on him, and on members of his family. A quote in the frontispiece reads: The people were saying no two were e'er wed But one had a sorrow that never was said.
The book is divided into three main parts, of two chapters each. These chapters are further subdivided into a series of short stories in strict chronological order, anchored in time by month and year, with short precise titles such as "Feet";“Father”; “Mother”; and “Crazy Joe”. This structure provides the reader with telling glimpses of crucial events in the narrator’s life: the gloom of grinding poverty and injustice is relieved at times by hilarious and vivacious dialogue. There is a strong emphasis on the division between Catholics and Protestants and how it affected everyone. The power of the Church and the authority of police, atheism versus faith, the nature of courage, subjugation by various hierarchies, family loves and loyalties, the yearning for education, and the impact of economic hardship are central themes .
Seamus Deane has often been asked why "Reading in the Dark" was not called a memoir rather than a novel, because Deane's upbringing was almost identical to that of the main protagonist, but he usually avoids giving a straight answer, which raises the question for some readers about how much truth lies in fiction.