Keys to the Demon Prison (Fablehaven, #5)

After many centuries of plotting, the Sphinx -- leader of the Society of the Evening Star -- is after the five artifacts needed to open the great demon prison, Zzyxx. Kendra, Seth, and the Knights of the Dawn are in a race to strange and exotic preserves across the globe in an effort to intercept the final artifacts. The stakes have never been higher. The risks have never been more deadly as the forces of light and darkness collide at last.