To Chrenton and the Lollers of the Bowl, the caps are everything. The caps form their homes, their food, their rituals, and their songs. It's a world where light is rare, songs are history, and wisdom is sought from the Great Toad.

But, for the first time in their memory, things are changing. The rivers feeding their home are slowing. The caps are dying. Not even the Great Toad on his damp throne can help them.

Chrenton, his friend Allast, and the odd Peetro are tasked with venturing beyond their valley to a foreign land where no caps grow and their cherished songs seem strange. There, they must find a way to save their home without drawing the hungry forces of the wastes in to devour it.