The Hidden Kingdom - Nocturnals, Bk 4 Author:Tracey Hecht, Sarah Fieber In The Nocturnals: The Hidden Kingdom, animals in the valley start to trip on the crumbling ground beneath them, water disappears, and disembodied voices are heard. Everyone assumes the forest is under an evil spell. It's up to The Nocturnal Brigade -- Dawn, Tobin, and Bismark -- to solve this mystery and unite the forest.