Destroy all monsters
(Book)

Ash does not remember the day she fell out of her friend Solomon's tree house, but ever since that day Solomon has retreated into a dark fantasy world and Ash believes the key to saving him is recovering her lost memory.

When they were twelve, Ash fell from Solomon's tree house. She's lost all memory of the events leading up to the fall but since then Solomon has retreated further and further into a world that he seems to have created in his own mind. One that insulates him from reality, but crawls with foes and monsters, in both animal and human form. As he slips further into the place he calls Darkside, Ash realizes her only chance to free her best friend from his pain is to recall exactly what happened that day in his backyard and face the truth. -- adapted from jacket