It's full-fledged war as Briar, the rat creatures and the Pawn army storm the city of Atheia where the Bones, thorn and Grandma Ben are up in arms to defend the royal city. When Thorn hears a voice urging her to seek the Crown of Horns, Thorns and Fone Bone embark on another dangerous journey as they race to find the one thing that mat save them all.