When an EMP cripples the electrical grid, John Sheridan, a guilt-ridden veteran, is left stranded in the Black Hills with failing vision and a mysterious local girl. Alone in a remote cabin, John must confront both his past and a dark secret as survival takes on new urgency in the face of a nationwide blackout.
Meanwhile, his daughter Laura refuses to evacuate her Florida home without her surviving son, braving a deadly hurricane to reach him. But her journey through chaos attracts dangerous attention, forcing her to face threats greater than the storm itself.
As darkness falls and desperation rises, both father and daughter must risk everything to protect what remains of their fractured family. But in a world stripped of order, will they find each other in time?
