The novel opens in the Welsh mining town of Aberowen on June 22, 1911. Billy Williams is woken up by his father early in the morning of his 13th birthday; It is his first day working in the town’s coal mine. Billy lives with his family in a simple home. There is no running water, and the street shares a communal toilet.

Billy’s family, including his 18-year-old sister Ethel, his mother, his grandfather, and his father, wish him well for his first day. Billy and his friend Tommy walk to the mine and are received by Perceval Jones, the Chairman of Celtic Minerals (the company that runs the coal mines in the area). Jones’s antipathy toward both boys’ families is made clear. The boys are allocated to deputy manager Rhys Prince, and they descend into the mine via a cage. Billy is ashamed when he screams in fear as the cage plummets down the deep shaft. Once down in the mine, he is given the task of shoveling coal dust into a dram (a mining cart) in a distant tunnel. Price tricks Billy, swapping his lamp for one that is low on oil. Price leaves Billy to his work, and the lamp soon goes out, leaving Billy alone in the dark for the rest of the day.