President Bartet's attack of multiple sclerosis requires hasty reorganization of the summit in China. Unable to endure the long meetings, he becomes frustrated when the Chinese take advantage of his absence to drag their feet over North Korea. Back at the White House, Josh is told by NASA that a large asteroid is on a collision course with earth; staffers are unsure whether to prepare for the end of the world or not. Donna becomes frustrated when Josh continually postpones what she says is an important conversation. With the New Hampshire primary looming and Vinick looking like a formidable opponent, Josh and Leo try to find a Democratic presidential candidate they can believe in.

The Vinick campaign struggles with the impact of the nuclear accident in California; Josh and Donna have a "moment".

Santos and his staff prepare for the inauguration as Bartlet and his team look back on their years in the White House.