Australia has been annexed, the United Nations is in chaos, the world is under siege and the Ethereals have taken the field. Facing the full might of the Ethereal Collective, the Commander must rally XCOM, the newly formed ADVENT, and several other allies and rivals to unite the divided nations by any means necessary, for failure now will mean the fall of humanity once and for all.

After the destruction of the dreadnought, tensions between XCOM and the Council are higher than ever. Despite growing opposition and oversight, the Commander doesn't hesitate to push humanity further into uncharted territory, as well as dealing with an ancient global conspiracy, and a growing number of countries looking to take advantage of an invasion that is only just beginning.