A dying Guatemalan child in a Texas hospital brings immigration to the fore. A mugging opens Kirkman's eyes to the realities of life in the capital.

A stray Russian bomber jeopardizes Seattle, Mars crusades against a drug company, and an event from Aaron's childhood vexes Kirkman's campaign.

Kirkman mobilizes a frantic hunt for the bioterrorist. Lorraine plays hardball and pushes the opioid epidemic into the campaign fray.

Trailing in the polls, Kirkman weighs forcing the FBI's hand over the bioterrorism plot. Emily struggles with her mother's final wishes.