Izzy is an eighteen-year-old college student whose deep fear of flying is compounded by a plane crash. She carries a persistent fear of abandonment stemming from her parents' emotional distance and frequent absences. She eventually attends law school and takes a job as a congressional aide for a politician sponsoring an anti-war bill.

Nate is a nineteen-year-old soldier who joins the military to pay for college tuition so he can become an English teacher. Raised in an abusive household in Illinois, he develops an overwhelming instinct to shield others from harm. This drive shapes his career in the Special Forces as well as his personal relationships, though it often leaves him emotionally guarded and reluctant to commit.

Serena is Izzy's older sister and a daring photojournalist. Having grown up with largely absent parents, she takes on a maternal role for Izzy. Her professional assignment to document the political conflict in Mazar-i-Sharif becomes the catalyst that pulls Izzy into a dangerous war zone.

Jeremy is the ambitious son of a politician and Izzy's fiancé. Wealthy and politically connected, he represents the type of advantageous alliance Izzy's parents desire for their own social and financial gain. He views relationships as pragmatic arrangements rather than emotional commitments and expects Izzy to conform to his lifestyle.

Julian is a soldier and Nate's closest friend in the military. He encourages Nate's ambitions to join the Special Forces and serves as his primary confidant. He is one of the few people who knows the complete story of Nate's past with Izzy and the plane crash.

Taj is an Afghan local who works as an interpreter for Serena in Mazar-i-Sharif. He relies on securing an official visa to safely evacuate the country during the military withdrawal.

Senator Lauren is a US politician sponsoring a bill to end the war in Afghanistan. She employs Izzy as an aide and directs the delegation's movements during the chaotic withdrawal from Kabul.

General Webb is Nate's commanding officer in Afghanistan. He oversees the protection details for the congressional delegates and attempts to manage the escalating crisis as hostile forces approach Kabul.

Fitz is one of Nate's military friends. He is present when Nate and Izzy unexpectedly reunite in Georgia and expresses shock upon learning the truth about the plane crash, as Nate is usually highly secretive about his past.

Sergeant Gray is a member of the military detail in Afghanistan who assists with security at the embassy. He is observant of the dynamic between Nate and Izzy and follows orders to handle conflicts within the compound.