Interstitial ghosts is an account of a questing beast of a research project in pursuit of my doctoral creative and critical thesis. Like all questing beasts it has taken several unexpected twists as the researcher has followed the spoor of the primary concept: that sword-&-sorcery, particularly Robert E. Howard's initiating form of the genre can potentially exist as a kind of ghost genre or genre of echoes, in fact a mode rather than a genre. The essay incorporates metafictional techniques, balancing storytelling and academic methods in an unorthodox attempt to not only give an account of the research but an account of the research process. It begins by investigating the term 'mode', suggesting a worldview implied by Howard's fantasy stories and discusses earlier forms of fragmentary literature before characterizing the type of intensity engendered by both of these. The essay attempts to identify some of the symbols that recur in Howard's fantasy fiction and notes where these have influenced later sword-&-sorcery writers, before following the questing beast in attempting a poetic tarot of such elements and finally testing this by reference to and analysis of two texts which pre-date the Howardian creation of a distinctive sword-&-sorcery form.