In the aftermath of a deadly attack on the White House, Elizabeth tries to keep a major nuclear disarmament deal from falling apart while a manhunt for the attackers brings D.C. to a halt. For advice, Elizabeth turns to former secretaries of state Madeleine Albright, Hillary Clinton and Colin Powell.

When Elizabeth discovers that the White House attackers had support from overseas, she tries to hunt down those responsible without starting a war. Also, Henry comes face to face with one of the attackers.

Elizabeth flies to Fashion Week in Milan to face off against the Chinese Foreign Minister over an anti-sweatshop treaty in the aftermath of a tragedy. Also, Daisy struggles with feelings of fear and pessimism over her baby’s future, under the threat of rising nationalism in the wake of the attack on the White House.

When the remains of U.S. soldiers who served in World War II are uncovered in Southeast Asia, Elizabeth’s hopes of bringing them home quickly fade when a stubborn leader stands in her way. Also, Henry and Stevie find themselves publicly targeted by a restaurant owner who is angry about Elizabeth’s policies, and Alison volunteers for a local congressional campaign.

Henry finds himself at the center of an international incident, when he comes to the aid of an ex-girlfriend at a religious freedom conference in Thailand, after she is imprisoned for condemning the monarchy. Also, Elizabeth helps Jason navigate the pressure of preparing for college.

When the eruption of an Icelandic volcano strands Elizabeth at an airport in Ireland with the Turkish foreign minister, she tries to broker a deal with him to save the lives of thousands of Syrian refugees. Also, Henry gives advice to Alison about an awkward topic.

Vice President Teresa Hurst asks Elizabeth for help when a surrogate carrying her future grandchild is arrested in Laos for human trafficking. Also, Henry tries to protect Stevie from danger when he suspects that she’s being followed by a Russian operative, and Blake deals with the demanding and costly instructions of a delegation of Japanese gardeners.

When Haiti’s democracy is threatened by a president who refuses to step down after losing the election, Elizabeth tries to solve the problem without resorting to military action. Also, Blake has one week to find a new job before Elizabeth fires him as her assistant.

Elizabeth and Jay work to keep an historic agreement between Serbia and Kosovo from falling apart, after a mass grave is discovered in Serbia dating back to the Kosovo war. Also, Henry deals with a bizarre encounter with Secretary of Defense Gordon Becker.

Elizabeth goes head to head with a U.S. governor over the state's new policy of separating unauthorized immigrants from their children. Also, she and Henry plan to renew their wedding vows.

Elizabeth must salvage a deal with a military contractor by supplying fighter jets to Taiwan, but she risks triggering a war with China in the process. Also, Daisy gets frustrated with Matt for failing to help take care of her dog like he promised.

When innocent Syrian children are killed by an American-made cluster bomb, Elizabeth races to figure out what went wrong before Russia can use it as an excuse to escalate its military presence in the region. Also, Russell faces a PR nightmare after he gets into a heated argument with a homeless protester.

When a group of American missionaries become hostages during a violent uprising abroad, Dalton must confront demons from his past in order to help Elizabeth secure their safe return home. Also, Stevie takes over Russell’s social media presence, and Henry helps his niece, Sarah, mentally prepare for her military deployment.

Elizabeth visits the Middle East to finalize a deal to bring U.S. troops home, but complications arise when a local woman’s life is threatened by rumors of a romance with one of Elizabeth’s staffers. Also, Henry provides relationship advice to Elizabeth’s brother, Will.

When a super typhoon threatens a small Pacific island, Elizabeth tries to relocate its population before the storm makes landfall. Also, Henry gives a speech to an evangelical group about climate change.

While Elizabeth is away on a retreat thinking about her presidential campaign, her staff tries to secure an international agreement to protect citizens who have been displaced due to global warming. Also, the staff works to contain a measles outbreak that threatens the life of Daisy’s daughter, Joanna.

A NATO ally carries out a state-sponsored assassination attempt against one of its own citizens, who is also a U.S. resident and old friend of Elizabeth’s. Also, Alison starts dating the son of one of Elizabeth’s political rivals.

As Elizabeth prepares to officially declare her candidacy for president, she must deal with fallout from a news article alleging she had an affair with President Dalton during her CIA days. Also, Mike B. and Jay adjust to the growing pains in their expanded roles as campaign staffers, and Elizabeth calls for a UN criminal tribunal against Myanmar military leaders over their treatment of the Rohingya.

As Elizabeth prepares to leave the state department and announce her run for president, terrorists attack the United Nations delegation in Geneva that is there to sign the climate migration treaty.