Eldritch Horror: Signs of Carcosa - Rules of Play says:
Signs of Carcosa is a new expansion for Eldritch Horror, and within, you’ll find enough madness to influence all of your games. Hastur enters the game as a new Ancient One, spreading insanity and dissension. Against this foul abomination from Aldebaran, four new investigators join the fight to save the world. A host of new Encounter cards for every continent ensure that fresh adventures are always around the corner, even as a wealth of new conditions, spells, assets, artifacts, and Mythos cards draw you deeper into a world of madness and fear.