The most pervasive literary influence on this work is Welsh mythology. Not only are several place names evident, e.g., Annwn, but also objects, like the sacred harp, and episodes, like the search for the High One. A more immediate influence, not just on this novel but on the trilogy as a whole, is Ursula Le Guin's Earthsea quartet, which is also a coming-of-age narrative in an imaginary world.

Susan Cooper's Dark Is Rising series intertwines Celtic, Welsh and Arthurian legends in the story of Will Stanton who discovers he is the last of the "old Ones" and he must recover the crystal sword so that the Dark Rider can be vanquished. (Over Sea, Under Stone [1965]; The Dark Is Rising [1973]; Greenwich [1975]; The Grey King [1975]; Silver on the Tree [1977].)

The allegorical fantasy also has elements of Arthur Edward Waite's The Quest of the Golden Stairs: A Mystery...