Jonathan Duncan is the president of the United States. He is a former military serviceman who survived capture and torture, and he later trained as a lawyer. He hides a severe bleeding disorder from the public while working to stop a massive, impending cyberattack known as "Dark Ages." He operates with a high degree of secrecy, often leaving his own staff in the dark as he attempts to manage internal and external threats to the country.

Carolyn serves as the White House chief of staff and acts as one of Duncan's closest advisors. She is highly intelligent and fiercely ambitious. Her own political career was derailed years earlier when she used an expletive on a live microphone, leaving her resentful of the double standards in politics. She manages the president's schedule and controls the flow of information inside the White House.

Katherine Brandt serves as the vice president of the United States. She assumes temporary authority when Duncan disappears to conduct his secret meetings. She is an intelligent and capable politician who feels slighted by the president's lack of transparency. She engages in illicit meetings with the speaker of the House, raising questions about her loyalty.

Augie is a math prodigy in his twenties who grew up in Ukraine. He previously worked alongside the Sons of Jihad to develop the "Dark Ages" computer virus, viewing it initially as an intellectual challenge rather than an act of terrorism. After realizing the true devastation the virus will cause, he travels to the United States to help the president stop the attack.

Suliman is a Turkish terrorist who leads a group known as the Sons of Jihad. He is the mastermind behind the "Dark Ages" virus, which is designed to cripple the digital infrastructure of the United States. He is not motivated by religious ideology, but rather by greed and a desire to demonstrate his power on a global scale. He operates remotely from Europe, monitoring the progress of his attack.

Bach is an elite, highly trained assassin working for Suliman Cindoruk. She survived the Bosnian War as a child, a traumatic experience that left her entirely pragmatic about violence and death. She is in the early stages of pregnancy and views her lethal assignments as a way to secure financial stability for her unborn child. She constantly listens to classical music while executing her missions.

Lester Rhodes serves as the speaker of the House and acts as a fierce political antagonist to the president. He pushes heavily for Duncan's impeachment, using the ongoing public relations crisis to his advantage. He prioritizes his personal and political agendas, demanding favors in exchange for legislative leniency.

Nina is a young woman from the disputed region of Abkhazia in Georgia. She helped design the "Dark Ages" virus alongside Augie for the Sons of Jihad but defects in an attempt to stop the attack. She reaches out to the American government, hoping to exchange her knowledge of the virus for amnesty so she can safely return to her home country.

Lilly is President Duncan's daughter. She is studying abroad in France when she is abruptly pulled into the crisis by a stranger reciting a classified code word. She is quickly brought back to the United States to ensure her safety.

Rachel is the late wife of President Duncan. They met and fell in love while attending law school. Her memory provides the president with emotional grounding during his periods of intense stress.

Alex serves as the president's head of security. He manages Secret Service operations and actively tries to keep the president safe, even when Duncan intentionally breaks protocol to travel incognito.

Amanda is an actor and a longtime personal friend of President Duncan. She assists him by using her professional makeup and hairstyling skills to alter his appearance, assuming he is going on a date rather than undertaking a dangerous mission.

Liz is the newly appointed director of the FBI. Because she has only recently assumed her position, President Duncan knows she cannot possibly be the source of the leak inside the White House, making her one of his most trusted allies during the crisis.

Greg is the husband of Carolyn Brock, the White House chief of staff. He helps host the president and Augie when they use his residence as a temporary safe house while fleeing from assassins.

Devin is a skilled member of the elite cybersecurity team assembled in Virginia to combat the "Dark Ages" virus. He works directly with the president during the final, desperate attempt to input passwords to stop the attack.

Danny is a close personal friend of President Duncan. He serves as an emotional sounding board when the president experiences severe self-doubt about his ability to stop the cyberattack.