Summary:

In seventeen-year-old Lily Gonestar's world, humans and animals have evolved to meld together as one. Children can shape-change between humans and animals. At the age of eighteen, they must choose what animal form they will take on for the rest of their lives.
But there are always those that are different. In Lily's world, they are called Penneastrum. Lily is one of them. Able to shape-change for the rest of her life, she is an aberration, an oddity, told to go to the forest to live out her odd life. It is there that she meets Talim Kryer and his sister, Jessie, and is pulled into the battle against Evil and the cruel Penneastrum Salkar.