The novel recounts the life of a young man, Lucian Taylor, focusing on his dreamy childhood in rural Wales, in a town based on Caerleon. The Hill of Dreams of the title is an old Roman fort where Lucian has strange sensual visions, including ones of the town in the time of Roman Britain. Later it describes Lucian's attempts to make a living as an author in London, enduring poverty and suffering in the pursuit of art.