Bartlet orders a strike on the terrorist training camp as he and his staff broker a peace settlement between the Israelis and the Palestinians, but Bartlet and Leo realize that their differences over the peace settlement are irreconcilable, warranting a change in Leo's responsibilities. Having returned from Germany, Josh expresses concern about Leo's well-being, and his observations turn out to be well founded.

Margaret and Charlie prove to be invaluable allies as C.J. has a rough first day in her new position, made even more difficult by a Russian bearing radioactive gifts and a Defense Secretary's attempts to undermine her; Toby's less than stellar performance in the briefing room makes the search for a new press secretary a top priority, and Josh volunteers Donna to assist him in interviewing potential candidates; faced with a number of vulnerable seats in the upcoming election, Josh attempts to dissuade Matthew Santos from dropping out of another race for the House.

As acting chief of staff, Josh calls Leo in for backup when the news about Jed's health hits; the staff follows the progress of an asteroid headed for earth; Jed struggles with his relapse as C.J., Kate, and Toby handle the repercussions of his illness on the progress of the China summit; Josh is outraged when Will uses Jed's paralysis as a political opportunity for Russell; Donna resorts to extreme measures when Josh avoids her repeated attempts to sit down for a personal discussion; after receiving some wise advice from Leo about the future, Josh makes a decision about the man he'll support in the upcoming presidential election.

It's 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 the two front-runners, Vice President Russell and former Vice President 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 he may never be in. And Donna has a memorable encounter with a chicken.

Santos engineers a plot to get a stalled stem-cell bill scheduled for a vote in the House. President Bartlet has an uncomfortable reunion with a rival economist with whom he split the Nobel Prize. A group of underage kids tries to convince Toby they deserve the right to vote. Kate tries to resolve a silly border dispute with Canada before there is bloodshed.

At the Democratic National Convention, Russell, Santos and Baker jockey for the 2162 votes that will give one of them the nomination for President, and the opportunity to lose to the apparently unstoppable Vinick in November. Meanwhile, the President must make a decision before it's too late on whether to deploy a secret rescue mission to the space station, and the FBI is asked to determine who leaked the existence of the military shuttle to the press.

As they remain at Donna's bedside while she recuperates from surgery to remove a pulmonary embolism, Colin questions Josh about his personal relationship with Donna. When Bartlet and Leo clash over the appropriate response to the Gaza attack, Kate makes the case for a summit meeting, and provides Bartlet with the hook he needs to get the Israelis and Palestinians to sit down together at Camp David.

Santos starts up his presidential campaign in New Hampshire, where he immediately disagrees with Josh on campaign philosophy: "No opposition research, no dirt on our opponents." Josh has an uncomfortable reunion with Russell campaign staffer Donna.

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 before the corn growers association they must support subsidies for the use of corn-derived ethanol as fuel, regardless of their true feelings.

Santos is campaigning in California during the last few days before the all-important "Super Tuesday" primary elections, but he is out of money and he trails both Russell and Hoynes in the polls. When even "La Palabra", a Latino voters group, is all set to endorse Hoynes instead of Santos, Josh urges Santos to take a stand on the new bill that denies driver's licenses to illegal immigrants. Meanwhile, Donna tries to figure out why Hoynes suddenly isn't campaigning in California, and advances her position in the Russell campaign by becoming the Vice President's official spokesperson.

Penn and Teller roll a lesson about the First Amendment into their entertainment at Zoey's White House birthday party, setting off a media frenzy and public relations nightmare; Baker drops out of the race, leaving the field free for Russell, who asks Josh to run his campaign; Jed takes a hard line on making significant gains on substantive issues in his last China summit; Vinick turns down Jed's offer of the U.N. ambassadorship to run for president; a fully ambulatory Donna has difficulty scheduling a meeting with Josh; Jed has an MS relapse which leaves him partially paralyzed and in a wheelchair.

A new candidate for president, Senator Rafferty, has garnered much media attention with a ground-breaking speech about health care. But her words contain interesting echoes of President Bartlet's original health plan, which is known only to White House insiders, and reporter Greg Brock suspects that Rafferty is being secretly supported by the incumbent. Meanwhile, Toby is more than usually morose after the death of his brother. A bill to combat drought conditions in the western U.S. gives C.J. problems, particularly in dealing with lobbyist Clifford Calley. And Charlie tells Kate Harper that a man from his gym asked if she was dating anyone.

Leo is rushed into bypass surgery after suffering a massive heart attack; as Toby and Josh scramble chaotically to get votes after Haffley demands Democratic support for a tax cut in exchange for ratification of the peace plan, it becomes quickly apparent that Jed must overcome his reluctance to name a new chief of staff; C.J. works with the State Department on getting U.N. and NATO approval of the peace accord; Charlie drags his feet about completing some minor graduation requirements because he's reluctant to keep his promise that he'll resign as Jed's body man to seek a better position once he has his degree; Donna returns to work; C.J. gets on Josh's case about his unhealthy diet.

A senator attaches a rider to the federal budget bill that would ban gay marriage, almost daring the President to veto it, as the physical infirmities of Bartlet's MS become more pronounced. The Internet is rampant with a story that questions CJ's sexual orientation, and it is only fueled further when CJ refuses to dignify the allegations by putting out a statement. Donna joins the Vice President's senior staff, and heads for New Hampshire to start up Russell's presidential campaign there. And Santos decides that he will run for president after all, but only if Josh will leave the White House to manage his campaign.

On the day after Bartlet gives his last State of the Union address, Leo returns to the West Wing but has difficulty getting the attention of the rest of the staff for a meeting about what to do during the remaining 365 days of Barlet's term. Kate and C.J. have to deal with emergencies in Bolivia and North Korea. Charlie tries to figure out how to get Congress to support funding for the Earned Income Tax Credit. Toby solicits Annabeth's advice regarding proper behavior for Abbey at a NASCAR event. Will asks why they originally chose Russell to be Vice President. And Bartlet seems to have recovered most of his strength after his recent bout with MS.

Valentine's Day starts badly when the Iranian air force shoots down a British airliner, killing 100 passengers. The U.K. Prime Minister threatens to retaliate by bombing nuclear reactor sites, which could doom future support for political reformers in Iran. But C.J. has made an agreement with Abbey to allow the President to get more rest, and she is reluctant to awaken him at 5 A.M. to deal with the crisis. Meanwhile, Toby and a visiting law professor answer questions from a foreign delegation that is trying to write a new constitution for the former Soviet Republic of Belarus, and harried staffers pass the buck of Leo's traditional meeting with the new Miss World.

Senator Vinick, now the Republican Presidential nominee, receives advice from former Bartlet political consultant Bruno Gianelli on how to win all 50 states in the general election, and more specifically in the near term how to present his religious views to the public and pick a running mate. Meanwhile, Bartlet wrestles with getting a minimum wage hike passed by attaching it to a bill necessary to raise the debt ceiling, and with how to unify his party in the face of a three-way race for the Democratic nomination.

Faced with a Democratic party in disarray in the face of the strongest Republican challenger they have ever had, Bartlet asks Leo to take charge of the potentially chaotic Democratic National Convention, while Santos considers a party-unifying vice-presidential offer from front-runner Russell. Meanwhile, the International Space Station is leaking oxygen and a rescue of the three astronauts will be difficult, and Bartlet catches Charlie leaving Zoey's bedroom after a nighttime visit.

Hours before the CAFE standards amendment is defeated, Josh succumbs to the lure of test driving a monster SUV while shopping for a Prius and gets into a fender-bender that proves embarrassing to the administration, so he's saddled with heading up a task force on alternative energy sources; after hosting a surprise graduation party for Charlie, Zoey agrees to his taking her out to a thank-you dinner; Annabeth educates Toby on the art of "charm and disarm" in handling the press; Charlie is offered an attractive way out of his employment dilemma; Kate extents a hand of friendship and support to Donna; C.J. gets some crucial insight from Leo on keeping Jed healthy; Margaret's plan to redecorate Leo's former office meets with resistance from her new boss.

The peace mission suffers its first American casualty, whose father is sharply critical of the administration; Santos breaks ranks with the party by signing onto Republican legislation for a patient bill of rights when his own bill dies in committee; Margaret searches for a new office for Charlie; Leo struggles to recover his health, his strength, and his appetite with the help of his nurse, who looks after both his body and his soul with wisdom and determination; Donna, out of her wheelchair and onto crutches, is besieged by the media for interviews; C.J. has harsh words for Toby when he lets his personal feelings take him off-message in the briefing room; Leo contemplates a post-recovery job offer in the private sector before his nurse reminds him why he left there in the first place; Will calls Josh out about the staff's disrespect for Russell's candidacy; as Annabeth finds a way to turn around a bad news cycle, Toby admonishes C.J. about micro-managing the press office.

Hoynes throws his hat in the presidential ring, and asks Josh to join his campaign; Jed's health begins to deteriorate; Toby and Kate head the protocol negotiations with the Chinese over the arrangements for the upcoming summit, which is jeopardized when Jed mistakenly accepts a Taiwanese flag at the National Prayer Breakfast; Bernard takes his new position as head of the Gifts Unit to heart as he gives Charlie a hard time about retrieving the flag so that it can be returned; Josh has his hands full with a pro-Taiwanese senator holding a hard line on recognizing their independence; Bob Russell crashes an Oval Office photo op with the governor of Pennsylvania, who's also another potential presidential candidate.

New rumors about Fidel Castro's health cause the President to re-examine the economic sanctions against Cuba that haven't worked for 40 years, and he sends Leo McGarry to meet secretly with the Cuban dictator. The occasion causes C.J. to check into Kate Harper's past with the C.I.A., but she is unaware of a past encounter between Kate and Leo. Meanwhile, Charlie discovers the complexities of dealing with a termite invasion of the White House.