For generations, the Night Warriors have used their powers to enter the dream world and defend humanity. Now, they face their most terrifying enemy yet: Isabel Gowdie, witch and mistress of Satan.

Entombed for three centuries, her powers have grown stronger. Now her evil influence seeps through the earth, carrying the seeds of the Night Plague, a disease that twists souls into madness.

The only way to stop it is to find Isabel Gowdie's hidden prison. But time is short. Each night, more and more people fall to the Plague, and two of the Night Warriors are already infected ? they just don't know it yet...