Disaster builds on disaster.
The Earth shakes and begins the process of opening the Rio Sea, where once a great ocean thrived.
As the shaking continues, Yellowstone awakes, blanketing much of the continent with ash, and inducing a multi-year winter and famine for those who survived the quakes, volcano, and societal unrest.
The rules have changed. Competition is no longer king.
People and animals must adapt to a changed world, reliant on each other.