Amidst a backdrop of worldwide ecological and seismological chaos in the mid-2100s, the United States has been split in two by the "Great Flood". As a result of the polar ice cap melting, the Mississippi River has destroyed the central portion of the United States, causing an ill-equipped Federal Government to fail and literally cutting the country in half. These two halves are left to fend for themselves in the aftermath.
By 2161, it only takes a hint of unauthorized military preparation in Pacifica for the newly restored president to order a strike in the heart of Pacifican territory -- an outpost in the now dry San Francisco Bay. This strike leads to the unthinkable: an epic conflict with global implications fought on U.S. soil. As a soldier in this struggle, Mason Briggs uses explosive, terrain-deforming weaponry to change the face of battle: He not only destroys the land in his path, he outright transforms it to gain the strategic advantage in completely unscripted ways no game has ever seen. With such a devastating arsenal at hand, Briggs never leaves any battlefield the way he found it.