September returns to Fairyland only to discover her own shadow has escaped and become the new Queen of Fairyland-Below, a magical underground kingdom. This shadow-queen is stealing all the shadows from Fairyland's creatures, leaving them hollow and joyless. September must journey into this strange, inverted realm to confront her shadow self and restore balance, learning difficult truths about growing up and the parts of ourselves we try to leave behind. Her adventure is filled with wondrous creatures, clever puzzles, and profound questions about identity and responsibility.