The Sword of Elseerian: The White Mage Saga #2 (The Chronicles of Lumineia)

Led by the mysterious Master, the Harbingers have infiltrated the highest levels of the mage government. They mean to reveal the mages to the world—and then conquer it. To that end they have stolen the Sword of Elseerian, and intend to open the portal to Draeken's vast army.

But the fiends are gone.

In their place another entity lurks. Caged for eons, the Dark feeds on fear . . . and light. If unleashed on Earth it will devour every spark of illumination, until mankind is left in darkness absolute. Madness and terror will rob men of their minds. Each will become extensions of the Dark, flesh without a soul. The Oracle and her allies have a desperate plan, to retrieve the Sword of Elseerian before it can be used. If they fail the Dark will be released.

And the day will have its last dawn.