The world watches the aftermath of the Gaza attack on U.S. officials. The President learns that 82% of the American people, almost all of Congress, the Vice President and Secretary of Defense, the Joint Chiefs, and all of his staff aside from C.J. Cregg and Kate Harper want him to launch retaliatory military strikes immediately. Meanwhile, he tries to arrange peace talks between the Israelis and Palestinians at Camp David. Finally, he strikes one of three suggested targets and readies for the peace talks. Meanwhile, in Germany, Josh anxiously waits for Donna's recovery, leading to his feelings about her being questioned by Colin.

Josh returns to the US as Israeli-Palestinian peace talks at Camp David result in a momentous peace accord. President Bartlet fires White House Chief of Staff Leo McGarry, who was strongly against the talks. Moments later, Leo suffers a massive heart attack.

Josh crashes an SUV into a hybrid vehicle, causing a public relations disaster. He meets with environmental supporters who berate the White House for doing too little to beef up laws in this area, including raising fuel emissions standards; Josh points out that they have had seven years of a hostile Congress. Annabeth Schott decides she can coach Toby to do the White House's press briefings. Kate confronts Donna about her experiences in Gaza.

Santos gets friendly with Republicans over a Patients' Bill of Rights, and the first American soldier dies in the Gaza peacekeeping mission, upsetting Donna.

While preparing for the upcoming China summit, the Chinese are insulted by President Bartlet's acceptance of a Taiwanese independence movement flag at a prayer breakfast. Charlie must try and return the flag, which proves difficult. Meanwhile, C.J. has to agree to stipulations the Chinese are making in order to mend fences. Eventually at a performance by James Taylor that evening paying tribute to Sam Cooke, Jed confides to Abby that he did not see the flag. He could not tie his bow tie, has not been able to focus for over a day, and has lost the sight in his right eye. Meanwhile, former Vice President John Hoynes asks Josh to run his presidential campaign.

In China, an impaired Bartlet is having trouble sitting through meetings following his MS attack. In Washington, a NASA functionary warns that an asteroid could strike Earth, while Josh wonders who should be the next guy to occupy the Oval Office and puts off a talk with Donna about her future until she finally quits her job.

The presidential candidates journey to Iowa, where Democrats Russell and Santos, and Republican Vinick, are all told by their handlers that when they appear before the corn growers association they must support subsidies for ethanol as fuel, regardless of their true feelings. Vinick becomes the only candidate able to keep true to his convictions.

It is five days before the New Hampshire primary, and Josh is desperately trying to find a "silver bullet" that will get his candidate into the local debate between front-runners Russell and Hoynes. Then, Josh and Santos's disagreements over how to run the campaign come to a head when Santos hires Josh's ex-girlfriend Amy Gardner to help him prepare for the debate.

The loss of Josh to the Santos campaign has left the West Wing staff noticeably shorthanded. Meanwhile, a bill to combat drought conditions in the western U.S. presents problems for C.J., particularly in dealing with lobbyist Clifford Calley – whom Leo suggests as a replacement for Josh. Reporter Greg Brock investigates the possibility of the White House secretly supporting one of the presidential candidates. Senator Rafferty, a new contender, garners media attention with a ground-breaking speech, her words echoing President Bartlet's original health care plan known only to White House insiders. Asked about this, Toby, who since the recent death of his brother has been even more morose than usual, confronts Josh with his feelings of betrayal over Josh leaving. Their heated argument escalates into a short brawl. In the aftermath, Toby confesses to C.J. that his brother did not die of cancer, but committed suicide. Charlie attempts to play matchmaker for Kate.

As Super Tuesday approaches, the three Democratic candidates battle it out to win California as the state legislature passes a bill that would prevent illegal immigrants from obtaining driver's licenses.

When speculations fly surrounding the nexus between communist Cuba and the United States, President Bartlet is propelled into a dubious conundrum: continue secret talks with Cuba's ailing dictator and lift the longstanding embargo or to yield to bipartisan political pressure and reaffirm decades-old sanctions. Meanwhile, Leo and Kate learn that they have more in common than politics when a distant memory of corrupted elections and bar-room antics reveal a more intimate connection.

The well-organized Republican convention is making the Democrats look in disarray as the three candidates continue to battle for the nomination. Bartlet asks Leo to take control and organize the convention. Meanwhile, the International Space Station has a leak and is losing oxygen which jeopardizes the lives of the three astronauts aboard and morality and mortality are examined. And a super-secret space shuttle might help them but it is considered too sensitive to reveal, until someone has a different idea.

Despite the best efforts of the White House, there is still no presidential nominee at the Democratic National Convention. As convention chair, Leo sits down with representatives from the various campaigns, trying to organize proceedings despite in-fighting. Meanwhile, the lives of the three astronauts in the International Space Station are still hanging in the balance as their oxygen supply dwindles. The White House tries to deal with the aftermath of the leaked rumor of a military shuttle that can be used to save them. With voices on all sides furious, President Bartlet demands that the leaker's name be on his desk by Friday and has given the task to Toby and Kate Harper. Back at the convention, Josh is trying to work out where he can find the crucial votes needed to win Santos the nomination. With the belief that Hoynes' campaign is over, Josh asks his former boss to transfer his votes to Santos after the first ballot. Meanwhile, the Russell camp receives some bad news as Governor Baker suddenly becomes a viable candidate. At the White House, Kate and Toby meet the FBI agents in charge of interviewing people capable of leaking the shuttle information. The guilty party is facing ten years in a federal prison for releasing classified information. After being asked to drop out and support a candidate Santos gives a rallying speech to the delegates reminding them to vote with their hearts. Inspired by this, Barlett quietly intervenes and encourages holdout delegates to support Santos. Josh tells Leo they still need a vice president and that the choice for the candidate is Leo.