When a catastrophic solar event makes daylight lethal, a family is forced into nocturnal lockdown. Aunt Marlene is left watching over her niece Coraline, nephew Parker, Coraline’s boyfriend, and his friend while their parents are away. Each night, desperate strangers knock on the door seeking shelter. Some are human. Some are not. As the group decides who to let in and who to turn away, subtle signs begin to appear and the line between survivor and Visitor grows dangerously thin.