Publisher's blurb: Alien aberrations from the Far Realm seek to invade this world. They have been fought off before, by ancient defenders wielding a sky-blue rune, but the wards are weakening. Things writhing and slick lurk just beyond sight, pushing at the boundaries of their cage. Visions appear. Psychic powers manifest. The Cerulean Sign rises. Within these pages, you will find information on the Cerulean Sign, a forgotten rune whose keepers and adepts defend this world from aberrant infiltration. You will learn how to infiltrate cults, you will learn how to receive the blessing of the Cerulean Sign, you will learn how to wield psionic power, and you will become a defender of this world.