Evolution - Justice Keepers Saga, #5

Earth's fate hangs in the balance. The disgraced Justice Keeper Grecken Slade conducts a campaign of terror to gain control of the Key: a mysterious piece of Overseer technology. Facing him is Jena Morane, who leads a rag-tag band of resistance fighters to protect innocent civilians from Slade's wrath. Meanwhile, Jack Hunter and Harry Carlson search for the three ciphers that will grant them access to the Key, and the secrets buried therein.
After ten thousand years, the Overseers have returned... and the galaxy will never be the same again.