First Summer's Eve has come and all elves celebrate as the black moon's shadow fades from the world. It is also Luthiel's fifteenth birthday. With it come two extraordinary and dangerous surprises: a Wyrd Stone, its silvery heart a window into a world of dreams and nightmares, and a Blade Dancer, dreaded protector of the Faelands, who bears a dark message. Instead of celebration, Luthiel is given a terrible choice: if she does nothing, someone she loves deeply will die. Or to save a life, she can break the most perilous law of the Faelands, and venture alone to the Vale of Mists. If she chooses the journey, she must race Othalas -- eldest and most feared of all the werewolves -- past great back spiders who weave webs out of nightmares, through glittering mists with the power to reshape flesh, and at last into death by the teeth of dark and ancient Vyrl, who feed on the blood of elves. Either choice will bring death -- unless Luthiel can find the secret in her remarkable Stone, a secret that even the nightmares fear.