Book of the Wyrm is a storyteller's guide to all things concerning the Wyrm. In it includes Black Spiral Dancer gifts, sample characters, information on Banes, as well as Fomori and their gifts. There is also information on Bane Fetishes and Black Spiral Rites. The Book of the Wyrm greatly expands the mythos surrounding the wyrm and goes further into explaining the "Triat within the Triat" of the Wyrm.