The phrase refers to a hypothetical continuation of a well known fantasy saga. The preliminary sequence concluded with guide 14; thus, ‘guide 15’ signifies a possible, and at the moment nonexistent, extension to the unique narrative. Dialogue round this idea typically includes fan hypothesis, approved sequels, or doable spin-offs.
The importance lies within the enduring reputation and the wealthy universe established by the creator. The potential for additional exploration of that universe generates appreciable curiosity. Moreover, the hypothetical continuation carries the advantage of offering extra narratives and characters for devoted readers to take pleasure in, increasing the established lore and probably introducing new themes or views.