Keys to the Demon Prison is by Brandon Mull. The final book in the Fablehaven series finds Seth, Kendra, and their allies fighting to keep the Sphinx from opening the demon prison of Zzyxx. They fight to collect all the artifacts needed to open the prison and keep the ones they have from the Sphinx and the Society of the Evening Star. If they fail the world will be overrun by demons and everyone they love will die. Can they succeed and at what cost?
Ratings: 7th grade - 10 out of 10.