From the preview:
Eons ago, sentient life forms stronger and more ruthless than mankind ruled the earth. These Elder Things enslaved other species and built a civilization far more advanced than our own. But as earth’s climate changed, the Elder Things lost their power and withdrew to what is now Antarctica, waiting out the millennia for a time when they might rise again. In the Mountains of Madness expansion for Eldritch Horror, that time has come. The Elder Things are awakening, and you must prevent them from retaking control of the world.
Today’s preview focuses on the Rise of the Elder Things, one of the two Ancient Ones that you can combat in Mountains of Madness. We will also look at the expansion’s Adventures, which guide your Antarctic expedition and reward you for braving the continent’s terrible conditions and terrifying horrors.