Like most of Kurtz's books, The Harrowing of Gwynedd is written in a nonobtrusive style, with third-person narration and a straightforward sequence of events. The viewpoint changes as the story shifts back and forth between scenes involving the several major characters.

One unusual feature of the author's style is the attention she gives to visual image-building. In the novels which feature warfare, the descriptions of feudal panoply—the bright banners and glittering horses' harness and the warriors' colorful regalia—are painted in vivid and evocative detail. In the present book, passages about the invocation of powerful magic play a climatic part similar to that of battles in standard fantasy. These scenes of magical rites are described step by step so that the reader can visualize and almost feel the objects handled and the unseen powers that are being manipulated. This technique works...