John is a middle-aged widower and former colonel. He teaches military history at Montreat College in Black Mountain, North Carolina. He has a practical attitude stemming from his military background but is a deeply devoted father to his two daughters. When the power grid fails, the town council increasingly relies on his strategic expertise.

Makala is a supervising nurse for a cardiac surgical unit in Charlotte, stranded in Black Mountain after the blackout. She is a pragmatic professional who quickly guesses the cause of the technological failure. She uses her medical expertise to assist the townspeople and quickly forms a connection with John.

Washington is the head of campus security at Montreat College. He is an African American man in his early sixties and a former Marine drill sergeant. While students usually view him as a standard security guard, his military background becomes vital for maintaining order when the crisis strikes.

Charlie is the director of public safety for Black Mountain. He is dedicated to the welfare of the town's citizens and works closely with law enforcement and local leaders to implement martial law. He takes on the heavy responsibility of maintaining peace as the situation deteriorates.

Jen is John's mother-in-law. She is a wealthy Southern belle with strong nerves. She drives a 1959 Ford Edsel, which unexpectedly becomes a crucial asset for the family because it lacks the computer parts affected by the blast.

Elizabeth is John's sixteen-year-old daughter. She relies on her family for stability as her typical teenage life is abruptly upended by the blackout. She spends much of her time with her boyfriend as the crisis unfolds.

Jennifer is John's twelve-year-old daughter. She has Type 1 diabetes, which makes her particularly vulnerable in the new, technology-free world. She relies on a regular supply of refrigerated insulin to survive and enjoys playing with the family's dogs.

Kate is the mayor of Black Mountain. She keeps a cool head during the initial hours of the crisis, dealing with emergencies at the local nursing home and hospital while trying to establish a plan of action.

Doc Kellor is the town's general practitioner. He possesses a grim, realistic view of the medical challenges facing the isolated town and works to manage the dwindling medication supplies for the community.

Dan is the president of Montreat College. He is a thoughtful leader who recognizes the need to organize the student body for the town's defense, viewing John's military background as an essential asset.

Zach is one of the Matherson family's two golden retrievers. He is a rambunctious golden retriever. He provides his family with comfort and a sense of normalcy during the initial crisis.

Ginger is the Matherson family's second golden retriever. Like Zach, she is a lively part of the household, representing the peaceful, domestic life the family enjoyed before the power grid collapsed.

Ben is Elizabeth's teenage boyfriend. He finds himself caught up in the town's struggle for survival and stays close to the Matherson family as the situation escalates.

Tom is the chief of police in Black Mountain. He is an aggravated yet level-headed officer who coordinates with the town leaders to handle the immediate fallout of the blackout.

Jim is an ex-hippie living in Black Mountain. Because he drives a vintage Volkswagen van without a computer, he possesses one of the few functional vehicles in town and helps restore other older cars.

Tyler is Grandma Jen's husband and John's father-in-law. He is a patient at the nursing home and requires significant care, prompting his family to bring him home when conditions at the facility deteriorate.

Don is a pilot who flies into Black Mountain with early news from the outside world. He uses his aviation skills to fly reconnaissance missions for the town council.

Carl is the police chief from the neighboring town of Swannanoa. He approaches Black Mountain's leaders to form a mutual defense pact and share resources.