Divided We Fall deals with the United States torn apart by anti-government militia, the secession of an independent Texas and the destruction of Washington, D.C. after an attack by Reed Richards.
When America seems to fall apart under the recent developments, Captain America comes out of his retirement and starts fighting against militia armed with sentinels, alongside Thor and Iron Man. At the same time, an X-Men group lead by Kitty Pryde travels through the country to end the anti-mutant war started by the late William Stryker.
When Texas feels threatend, they launch a nuke headed towards New York, but the Ultimates can stop it before it hits. Meanwhile, the new President has to face charges that he shouldn't have become president, the result of a conspiracy by Mr. Morez who plans to take over Wyoming next.
Kitty and her group have to fight off anti-mutant civilians. They decide to continue to go the Southwest to find Stryker and former inmates of the camp. When they arrive there, they meet Nick Fury.