A series of extraordinary events mark the beginning of summer: earth tremors ravage the Hyddenworld; Jack and Katherine have a child, Judith; and a mysterious gem is found near Brum. That same night, after decades of sleep, the Emperor of the Hyddenworld awakens . . .

Jack, born of the Hyddenworld, knows that he has a foot in each world but doesn't wholly belong to either.Is he human, or hydden? Judith too is a child of two worlds, with her human mother and hydden father. She knows who she is supposed to be - the Shield Maiden, bearer of the gems and helper of humankind - but somehow this destiny seems too much to accept.

The discovered gem puts Brum firmly in the path of the Empire - Jack must travel back to the Hyddenworld. He knows that the four gems need to be reunited soon and that the Shield Maiden must be ready to wield them.

If Judith does not embark on her own great journey soon, or the gems can't be found, then both the hydden world and the human will be threatened with extinction.